EP1253700A2 - Motor having rotatable shaft coupled with worm shaft - Google Patents
Motor having rotatable shaft coupled with worm shaft Download PDFInfo
- Publication number
- EP1253700A2 EP1253700A2 EP02009157A EP02009157A EP1253700A2 EP 1253700 A2 EP1253700 A2 EP 1253700A2 EP 02009157 A EP02009157 A EP 02009157A EP 02009157 A EP02009157 A EP 02009157A EP 1253700 A2 EP1253700 A2 EP 1253700A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- side rotator
- driving
- rotatable shaft
- shaft
- driven
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K5/00—Casings; Enclosures; Supports
- H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
- H02K5/14—Means for supporting or protecting brushes or brush holders
- H02K5/143—Means for supporting or protecting brushes or brush holders for cooperation with commutators
- H02K5/148—Slidably supported brushes
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
- H02K7/10—Structural association with clutches, brakes, gears, pulleys or mechanical starters
- H02K7/108—Structural association with clutches, brakes, gears, pulleys or mechanical starters with friction clutches
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
- H02K7/10—Structural association with clutches, brakes, gears, pulleys or mechanical starters
- H02K7/116—Structural association with clutches, brakes, gears, pulleys or mechanical starters with gears
- H02K7/1163—Structural association with clutches, brakes, gears, pulleys or mechanical starters with gears where at least two gears have non-parallel axes without having orbital motion
- H02K7/1166—Structural association with clutches, brakes, gears, pulleys or mechanical starters with gears where at least two gears have non-parallel axes without having orbital motion comprising worm and worm-wheel
Definitions
- the present invention relates to a motor including a clutch, which couples a rotatable shaft of a rotor to a worm shaft.
- one previously proposed motor used, for example, in a power window system includes a motor main body 52, a speed reducing unit 54 and a clutch 55.
- the motor main body 52 rotates a rotatable shaft 51.
- the speed reducing unit 54 includes a worm shaft 53 and transmits rotational driving force of the worm shaft 53 to a load side (e.g., a door window glass side of the power window system).
- the clutch 55 is placed between the rotatable shaft 51 and the worm shaft 53.
- the clutch 55 includes a driving-side rotator 61, a driven-side rotator 62, a collar 63 and rolling elements 64.
- the driving-side rotator 61 is connected to a distal end of the rotatable shaft 51 to rotate integrally therewith.
- the driven-side rotator 62 is integrally connected to a base end of the worm shaft 53.
- the collar 63 surrounds both the driving-side rotator 61 and the driven-side rotator 62 and is secured to a gear housing 56 of the speed reducing unit 54.
- the rolling elements 64 are arranged between the driven-side rotator 62 and the collar 63.
- each rolling element 64 is rotated together with the driving-side rotator 61 without being clumped between a corresponding control surface 62a of the driven-side rotator 62 and an inner peripheral surface 63a of the collar 63, and the driven-side rotator 62 is engaged with and is rotated by the driving-side rotator 61 in a rotational direction.
- each rolling element 64 is clamped between the corresponding control surface 62a of the driven-side rotator 62 and the inner peripheral surface 63a of the collar 63 to restrain the rotation of the driven-side rotator 62.
- the rotational driving force of the rotatable shaft 51 is transmitted to the worm shaft 53 through the clutch 55 to raise or lower the window glass.
- load e.g., weight of the window glass or vibrations of the window glass
- the rotation of the worm shaft 53 is restrained by the clutch 55 to restrain the unexpected downward movement of the window glass.
- the driving-side rotator 61 and the driven-side rotator 62 are installed such that a rotational axis of the driving-side rotator 61 is aligned with a rotational axis of the driven-side rotator 62. Furthermore, a connecting hole 61a is formed in a central portion of the driving-side rotator 61 to extend in an axial direction. A connecting portion 51a formed in a distal end of the rotatable shaft 51 is press fitted into the connecting hole 61a of the driving-side rotator 61, so that the rotatable shaft 51 and the driving-side rotator 61 are connected to each other to rotate together. Thus, it is required to assemble the motor such that the central axis of the driving-side rotator 61 (connecting hole 61a) and the central axis of the rotatable shaft 51 are aligned with each other.
- misalignment between the rotational axis of the driving-side rotator 61 and the rotational axis of the rotatable shaft 51 e.g., tilt of the rotational axis of the rotatable shaft 51 relative to the rotational axis of the driving-side rotator 61, or radial displacement of the rotational axis of the rotatable shaft 51 relative to the rotational axis of the driving-side rotator 61, which extends parallel to the rotational axis of the rotatable shaft 51
- tilt of the rotational axis of the rotatable shaft 51 relative to the rotational axis of the driving-side rotator 61 e.g., tilt of the rotational axis of the rotatable shaft 51 relative to the rotational axis of the driving-side rotator 61, or radial displacement of the rotational axis of the rotatable shaft 51 relative to the rotational axis of the driving-side rotator 61, which extends
- the present invention addresses the above disadvantages.
- a motor including a motor main body, a speed reducing unit and a coupling means.
- the motor main body includes a rotatable shaft and rotates the rotatable shaft.
- the speed reducing unit is connected to the motor main body and includes a worm shaft.
- the worm shaft is substantially coaxial with the rotatable shaft.
- the coupling means couples the rotatable shaft with the worm shaft.
- the coupling means includes a driving-side rotator and a driven-side rotator.
- the driving-side rotator is connected with the rotatable shaft to rotate integrally with the rotatable shaft.
- the driven-side rotator is connected with the worm shaft to rotate integrally with the worm shaft and is engageable with the driving-side rotator in a rotational direction.
- the rotatable shaft includes a connecting portion.
- the driving-side rotator includes a connecting portion, which is loosely fitted with the connecting portion of the rotatable shaft and is engageable with the connecting portion of the rotatable shaft in the rotational direction to rotate integrally with the connecting portion of the rotatable shaft.
- a motor including a motor main body, a brush holder, a speed reducing unit, a coupling means and a positioning means.
- the motor main body includes a yoke housing.
- the yoke housing rotatably receives an armature, which includes a rotatable shaft and a commutator.
- the brush holder is placed in an opening of the yoke housing.
- the brush holder holds a plurality of brushes in sliding contact with the commutator and includes a bearing, which rotatably supports the rotatable shaft.
- the speed reducing unit includes a gear housing connected to the yoke housing in such a manner that the brush holder is arranged between the opening of the gear housing and an opening of the yoke housing.
- the gear housing rotatably receives a worm shaft, which is substantially coaxial with the rotatable shaft.
- the coupling means couples the rotatable shaft with the worm shaft.
- the positioning means is placed between the brush holder and the gear housing for positioning the brush holder and the gear housing relative to each other.
- FIG. 1 is a schematic cross sectional view of a motor 1 used as a drive source of a power window system according to the present embodiment.
- the motor 1 includes a flat motor main body 2, a speed reducing unit 3 and a clutch (coupling means) 20.
- the motor main body 2 includes a yoke housing (hereinafter, simply referred to as a yoke) 4, a couple of magnets 5, a rotatable shaft 6, an armature 7, a commutator 8, a brush holder 9 and brushes 10.
- a yoke housing hereinafter, simply referred to as a yoke 4
- a couple of magnets 5 a rotatable shaft 6, an armature 7, a commutator 8, a brush holder 9 and brushes 10.
- the yoke 4 is shaped into a flat cup shape.
- the magnets 5 are secured to an inner peripheral surface of the yoke 4 and are opposed to each other.
- the armature 7 is arranged radially inward of the magnets 5 in the yoke 4.
- the armature 7 has the rotatable shaft 6.
- a base end of the rotatable shaft 6 is rotatably supported by a bearing 11 arranged at the bottom center of the yoke 4.
- the commutator 8 is secured to a predetermined distal end portion of the rotatable shaft 6.
- a connecting portion 6a which has diametrically opposing flat outer wall surfaces, is formed at the distal end of the rotatable shaft 6.
- two flanges 4a are formed to extend outwardly in a longitudinal direction of an elongated lateral cross-section of the yoke 4.
- the brush holder 9 is received within and secured to the open end of the yoke 4.
- the brush holder 9 includes a holder main body 9a and a connector 9b.
- the holder main body 9a is configured to substantially cover the open end of the yoke 4.
- the connector 9b is formed integrally with the holder main body 9a and protrudes outwardly from the holder main body 9a in a radial direction of the yoke 4.
- the brushes 10 are supported by the holder main body 9a.
- the brushes 10 are electrically connected to the connector 9b through electrical lines (not shown) and are slidably engaged with the commutator 8.
- a bearing 12 is supported at the center of the holder main body 9a.
- a clamp portion 9c extends along an entire outer peripheral edge of the holder main body 9a.
- the clamp portion 9c is clamped between the open end of the yoke 4 and an open end (opening) of a gear housing 21, which will be described below, along substantially an entire inner perimeter of the open end of the yoke 4.
- the clamp portion 9c is covered with an elastic seal member such that the seal member prevents penetration of water through the connection between the yoke 4 and the gear housing 21 when the clamp portion 9c is clamped therebetween.
- a couple of circular positioning holes 9d are provided radially inward of the clamp portion 9c at opposite diagonal corners, respectively, of the holder main body 9a.
- the positioning holes 9d are symmetrically arranged with respect the rotatable shaft 6 (i.e., each positioning hole 9d is equally spaced from the rotatable shaft 6) and penetrate through the holder main body 9a.
- Electric power is supplied to the brushes 10 from an external power source through the connector 9b.
- the electric power is supplied from the external power source to coil windings wound around the armature 7 through the brushes 10 and the commutator 8, the armature 7 (rotatable shaft 6), i.e., the motor main body 2 is rotated.
- the speed reducing unit 3 includes the gear housing 21, bearings 22a, 22b, a worm shaft 23, a worm wheel 24 and an output shaft 25.
- the gear housing 21 is made of a resin material.
- An open end (this open end is the top side in FIG. 1 and will be hereinafter referred as the top open end) of the gear housing 21, to which the motor main body 2 is secured, has a flat elongated cross section that corresponds with the open end of the yoke 4.
- Securing portions 21b are formed around the engaging recess 21a in the top open end of the gear housing 21.
- the flanges 4a of the yoke 4 are secured to the securing portions 21b to secure the yoke 4 to the gear housing 21.
- Three screw receiving holes 21c are formed at three predetermined positions in the securing portions 21b. A nut (not shown) is received in each screw receiving hole 21c.
- the gear housing 21 has a recess 21d that is recessed from a base of the engaging recess 21a at the center thereof.
- the recess 21d is elongated in a longitudinal direction of an elongated cross section of the engaging recess 21a.
- the gear housing 21 further includes a clutch receiving circular recess 21e and a worm shaft receiving portion 21f (FIGS. 2 and 3).
- the clutch receiving recess 21e is further recessed from a base of the recess 21d at the center thereof.
- the worm shaft receiving portion 21f is further recessed from a base of the clutch receiving recess 21e at the center thereof in the axial direction of the rotatable shaft 6.
- the gear housing 21 further includes a wheel receiving portion 21g.
- the wheel receiving portion 21g is communicated with the worm shaft receiving portion 21f in a direction perpendicular to an axial direction of the worm shaft receiving portion 21f at an axially middle portion of the worm shaft receiving portion 21f (i.e., the wheel receiving portion 21g is located on the right side of the worm shaft receiving portion 21f in FIG. 1).
- annular flange engaging recess 21h is formed at an open end of the clutch receiving recess 21e.
- Opposed engaging recesses 21i extend continuously from the engaging recess 21h in the longitudinal direction of the elongated lateral cross-section of the recess 21d.
- each base portion 21j is formed to surround the corresponding engaging recess 21i. That is, each base portion 21j is horseshoe-shaped and has a peripheral wall surface that is continuous with a wall surface of the engaging recess 21i. Each base portion 21j has opposite ends that are located adjacent to the lateral end sides of the lateral cross-section of the recess 21d, respectively. Cylindrical engaging projections 21k are formed in top surfaces of the opposite ends, respectively, of each base portion 21j.
- a bearing support portion 211 protrudes from the base of the clutch receiving recess 21e.
- the cylindrical bearing support portion 211 is flexible in a direction perpendicular to the axial direction.
- the bearing support portion 211 is shaped into a generally cylindrical shape and has an inner diameter, which is larger than an inner diameter of the worm shaft receiving portion 21f, and an outer diameter, which is smaller than an inner diameter of the clutch receiving recess 21e.
- the bearing support portion 211 generally extends to the center of the clutch receiving recess 21e in the axial direction.
- eight ribs 21m are arranged at equal angular intervals (45 degrees) along an outer peripheral surface of the bearing support portion 211 at the base end thereof.
- the ribs 21m are connected to an inner peripheral surface of the clutch receiving recess 21e.
- the bearings 22a, 22b are radial bearings made of a metal material (metal bearings).
- the bearing 22a is received in the bearing support portion 211.
- An inner diameter of the bearing 22a is smaller than the inner diameter of the worm shaft receiving portion 21f.
- the bearing 22b is engaged with an inner peripheral surface of a base portion (bottom side in FIG. 1) of the worm shaft receiving portion 21f.
- a couple of cylindrical positioning projections 21n are provided in the base of the recess 21d of the gear housing 21 in opposed relationship to the positioning holes 9d, respectively, of the brush holder 9.
- Each positioning projection 21n extends in the axial direction and is engaged with the corresponding positioning hole 9d.
- the positioning projections 21n and the positioning holes 9d constitute a positioning means.
- the clamp portion 9c of the brush holder 9 is received in the engaging recess 21a of the gear housing 21.
- the clamp portion 9c is covered with the elastic seal member, so that the clamp portion 9c cannot achieve accurate positioning.
- the brush holder 9 and the gear housing 21 are positioned relative to each other by the positioning projections 21n of the gear housing 21 and the positioning holes 9d of the brush holder 9.
- accumulation of errors between the rotatable shaft 6 and the worm shaft 23 is reduced, so that misalignment between a rotational axis of the rotatable shaft 6 and a rotational axis of the worm shaft 23 (e.g., tilt of the rotational axis of the rotatable shaft 6 relative to the rotational axis of the worm shaft 23, or radial displacement of the rotational axis of the rotatable shaft 6 relative to the rotational axis of the worm shaft 23, which extends parallel to the rotational axis of the rotatable shaft 6) is more effectively reduced.
- the worm shaft 23 is made of a metal material and includes a worm shaft main body 28 and a driven-side rotator 29 that is integrally formed with the worm shaft main body 28 on a motor main body 2 side of the worm shaft main body 28, as shown in FIG. 4.
- the worm shaft main body 28 has a worm 28a in the axially middle part thereof.
- the worm shaft main body 28 is rotatably supported by the bearings 22a, 22b at the opposite ends thereof and is received within the worm shaft receiving portion 21f.
- a contact member 26 is provided in a motor main body 2 side end surface (end surface of the driven-side rotator 29) of the worm shaft 23 at a position where a ball 36 (described below) contacts the worm shaft 23.
- the contact member 26 makes a point contact with the ball 36.
- the contact member 26 is made of a metal material (hardened metal material) having rigidity higher than the rest of the worm shaft 23 to restrain excessive wearing of the contact portion of the contact member 26, which contacts the ball 36.
- the worm wheel 24 is meshed with the worm 28a and is received within the wheel receiving portion 21g in such a manner that the worm wheel 24 is allowed to rotate about its rotational axial, which extends in a direction (direction perpendicular to the drawing surface in FIG. 1) perpendicular to the worm shaft 23.
- the output shaft 25 is connected to the worm wheel 24 in such a manner that the output shaft 25 coaxially rotates with the worm wheel 24 when the worm wheel 24 is rotated.
- the output shaft 25 is drivingly connected to a known window regulator (not shown) for raising and lowering a window glass.
- the rotatable shaft 6 is connected to the worm shaft 23 via the clutch 20.
- the clutch 20 includes the driven-side rotator 29, a collar 31, a plurality (three in this embodiment) of rolling elements 32, a support member 33, a stopper 34, a driving-side rotator 35 and the ball 36.
- FIG. 3 shows the structure around the rotatable shaft 6, which is rotated 90 degrees with respect to the rotatable shaft 6 shown in FIG. 2.
- FIG. 2 is a cross-sectional view corresponding to FIG. 6B, which is a cross-sectional view taken along line VIB-VIB in FIG. 6A (i.e., FIG 2 also shows the cross-sectional view taken along line VIB-VIB in FIG. 6A).
- FIG. 3 is a cross-sectional view corresponding to FIG. 7B, which is a cross-sectional view taken along line VIIB-VIIB in FIG. 7A (i.e., FIG 3 also shows the cross-sectional view taken along line VIIB-VIIB in FIG. 7A).
- the collar 31 includes a cylindrical outer ring 31a, an annular flange portion 31b and a couple of engaging portions 31c.
- the annular flange portion 31b extends radially outwardly from one end (upper end in FIGS. 2 to 4) of the cylindrical outer ring 31a.
- the engaging portions 31c are angularly spaced 180 degrees apart from each other and protrude radially outwardly from the flange portion 31b.
- the outer ring 31a of the collar 31 is fitted within the clutch receiving portion 21e.
- the flange portion 31b of the collar 31 is fitted to the flange engaging recess 21h.
- the engaging portions 31c are fitted within the engaging recesses 21i, respectively, so that rotation of the collar 31 is prevented.
- the other end (lower end in FIGS. 2 and 3) of the outer ring 31a of the collar 31 is inserted to a point near a distal end of the bearing support portion 211 (top end in FIGS. 2 and 3) and does not interfere with the flexing of the bearing support portion 211.
- the driven-side rotator 29 is positioned inward of the outer ring 31a.
- the driven-side rotator 29 includes a shaft portion 29a and three engaging projections 29b.
- the shaft portion 29a extends coaxially from a base end of the worm shaft main body 28 on the motor main body 2 side (rotatable shaft 6 side).
- the engaging projections 29b extend radially outwardly from the shaft portion 29a and are arranged at substantially equal angular intervals (about 120 degrees).
- Each engaging projection 29b has a progressively increasing circumferential width that increases toward a radially outer end thereof.
- FIG. 10 which is a cross sectional view taken along line X-X in FIG. 2, a radially outer surface of each engaging projection 29b constitutes a control surface 41.
- Each control surface 41 is spaced from an inner peripheral surface 31d of the outer ring 31a of the collar 31 for a distance that varies in a rotational direction or circumferential direction.
- Each control surface 41 of the present embodiment is a flat surface that is spaced from the collar 31 for a distance that decreases toward each circumferential end of the control surface 41.
- the driven-side rotator 29 includes reinforcing ribs 29c for reinforcing the engaging projections 29b.
- Each reinforcing rib 29c is formed to connect circumferentially opposed lateral surfaces of each circumferentially adjacent pair of engaging projections 29b.
- Each rolling element 32 is made of a resin material and is shaped into a generally cylindrical shape. Furthermore, as shown in FIG. 10, each rolling element 32 is arranged between the control surface 41 of the corresponding engaging projection 29b and the inner peripheral surface 31d of the collar 31.
- An outer diameter of the rolling element 32 is smaller than a distance between a center portion (circumferential center) 41a of the control surface 41 and the inner peripheral surface 31d of the collar 31 but is longer than a distance between each of end portions (circumferential ends) 41b, 41c of the control surface 41 and the inner peripheral surface 31d of the collar 31. That is, the outer diameter of the rolling element 32 is equal to a distance between the inner peripheral surface 31d of the collar 31 and each intermediate portion 41d located between the center portion 41a and each circumferential end 41b or 41c.
- the support member 33 rotatably supports the rolling elements 32 in such a manner that the rolling elements 32 are arranged parallel to one another at substantially equal angular intervals. More specifically, with reference to FIGS. 2 to 4, the support member 33 is made of a resin material and includes a ring 33a, three inward protrusions 33b, three pairs of roller supports 33c and three connectors 33d.
- the ring 33a is formed into an annular shape having an outer diameter larger than that of the outer ring 31a.
- the inward protrusions 33b extend radially inwardly from an inner peripheral surface of the ring 33a and are circumferentially arranged at substantially equal angular intervals.
- Each pair of roller supports 33c is provided to each inward protrusion 33b.
- the paired roller supports 33c extend axially from circumferential ends, respectively, of the corresponding inward protrusion 33b at a radially inward region of the inward protrusion 33b.
- Each connector 33d is formed into an arcuate shape that connects one roller support 33c of one pair to the following roller support 33c of the next pair.
- two circumferentially opposing engaging projections 33e are formed in distal ends of the roller supports 33c.
- Each rolling element 32 is held between the paired roller supports 33c and also between the inward protrusion 33b and the opposing engaging projections 33e in such a manner that the rolling element 32 is immovably held with respect to the ring 33a in a circumferential direction and also in an axial direction.
- the support member 33 which holds the rolling elements 32 in the above-described manner, is positioned such that each roller support 33c is inserted into the inside of the outer ring 31a to position each rolling element 32 between the corresponding control surface 41 and the inner peripheral surface 31d of the collar 31, and the ring 33a abuts against the flange portion 31b in the axial direction.
- the stopper 34 is made of a metal plate having a generally uniform thickness throughout it.
- the stopper 34 includes an annular engaging part 34a and a pair of extended parts 34b.
- An inner diameter of the engaging part 34a is substantially equal to the inner diameter of the ring 33a of the support member 33.
- the extended parts 34b are angularly spaced 180 degrees apart from each other and protrude radially outwardly from the engaging part 34a.
- an inner diameter and the outer diameter of the engaging part 34a are substantially the same as the inner diameter and the outer diameter, respectively, of the cylindrical outer ring 31a of the collar 31.
- Each extended part 34b includes securing portions 34c.
- the securing portions 34c are provided at four corners, respectively, of the stopper 34 in such a manner that positions of the securing portions 34c correspond to the positions of the corresponding engaging projections 21k, respectively, of the gear housing 21.
- the engaging projections 21k are inserted into the securing portions 34c, respectively, to secure the stopper 34 to the gear housing 21.
- the engaging part 34a of the stopper 34 is placed over the ring 33a of the support member 33 (placed at the top side in FIG. 1). Once the ring 33a of the support member 33 abuts against the engaging part 34a of the stopper 34, the stopper 34 prevents axial movement of each rolling element 32 in cooperation with the support member 33.
- each extended part 34b has a limiting portion 34d at the center thereof.
- Each limiting portion 34d is formed by cutting the corresponding center portion of the extended part 34b and then bending it obliquely. A distal end of each limiting portion 34d abuts against the corresponding engaging portion 31c of the collar 31 to restrain the axial movement of the collar 31.
- the driving-side rotator 35 includes a shaft portion 35a, a disk portion 35b and a ball holding portion 35c.
- the disk portion 35b has an outer diameter larger than that of the shaft portion 35a.
- the ball holding portion 35c is formed in the center of the disk portion 35b.
- a ball receiving recess 35d for holding the ball 36 is formed in the ball holding portion 35c.
- the ball 36 is held in the ball receiving recess 35d in such a manner that the ball 36 partially protrudes from the ball receiving recess 35d in both axial directions and is engaged with an end surface of the rotatable shaft 6 at one axial end and with the end surface of the worm shaft 23 (contact member 26) at the opposite axial end.
- the ball 36 is made of a hardened metal material to achieve the higher rigidity.
- a connecting hole 35e axially extends through the axial center of the driving-side rotator 35 from a base end (top end in FIGS. 2 and 3) of the shaft portion 35a to the ball holding portion 35c.
- the connecting hole 35e acts as a connecting portion and has two diametrically opposing flat inner wall surfaces.
- the connecting portion 6a of the rotatable shaft 6 is loosely fitted within the connecting hole 35e. That is, a size of the connecting hole 35e is larger than a size of the connecting portion 6a of the rotatable shaft 6 by a predetermined amount, so that a space S is formed between the connecting hole 35e and the connecting portion 6a of the rotatable shaft 6.
- the driving-side rotator 35 is drivingly connected to the rotatable shaft 6 to rotate together by loosely fitting the connecting portion 6a of the rotatable shaft 6 within the connection hole 35e.
- the driving-side rotator 35 of the present embodiment is formed by insert molding a metal plate 37 within a resin body having a shape generally corresponding to the shape of the driving-side rotator 35. Then, an elastomer material is integrally molded to the resin body to form a resilient holding portion 38 and cushion members 43, which will be described later.
- the metal plate 37 has a disk portion 37a and three arm portions 37b.
- the disk portion 37a of the metal plate 37 is insert molded within the disk portion 35b of the driving-side rotator 35.
- Each arm portion 37b extends radially outwardly from the disk portion 37a to a corresponding protrusion 42, which will be described later.
- the metal plate 37 is inserted within the driving-side rotator 35b to improve the rigidity of the driving-side rotator 35, particularly the rigidity of each protrusion 42, which is engaged with the driven-side rotator 29 to transmit driving force to the driven-side rotator 29, and also the rigidity of the connecting hole 35e, which is connected with the connecting portion 6a of the rotatable shaft 6 to transmit driving force from the rotatable shaft 6 to the driving-side rotator 35.
- a connecting hole 37c is formed in the center of the disk portion 37a of the metal plate 37.
- the connecting hole 37c acts as an engaging hole and is disposed in the connecting hole 35e.
- a cross sectional shape of the connecting hole 37c substantially coincides with that of the connecting hole 35e.
- An inner peripheral surface of the connecting hole 37c is flushed with an inner peripheral surface of the connecting hole 35e.
- the driving-side rotator 35 is molded by pouring a resin material in a molding die (not shown). In this process, the metal plate 37 is previously positioned in the molding die before the resin material is poured into the molding die.
- the connecting hole 37c is used to position the metal plate 37 in the molding die.
- the connecting hole 35e in which the connecting hole 37c of the metal plate 37 is disposed, is engaged with the connecting portion 6a of the rotatable shaft 6 in the rotational direction.
- the axial size of the connecting hole 35e is relatively small, the rigidity of the connecting hole 35e is increased by the metal plate 37.
- the rotational driving force transmitted from the rotatable shaft 6 can be effectively conducted to the driving-side rotator 35 while the axial size of the driving-side rotator 35 is minimized.
- an allowed tilt angle of the rotatable shaft 6 relative to the driving-side rotator 35 is increased.
- the resilient holding portion 38 which is made of a resilient elastomer material, is integrally molded to the driving-side rotator 35 such that the resilient holding portion 38 continuously extends from an open end of the connecting hole 35e.
- the resilient holding portion 38 is resiliently engaged with the flat outer wall surfaces of the connecting portion 6a of the rotatable shaft 6.
- a plurality (three in this embodiment) of generally fan-shaped protrusions 42 which extend radially outwardly and also extend in the axial direction, are arranged at substantially equal angular intervals on the distal end side (bottom side in FIG. 2) of the disk portion 35b of the driving-side rotator 35.
- Each protrusion 42 includes an arcuate outer surface, which circumferentially extends along the inner peripheral surface 31d of the collar 31.
- the arcuate outer surface of each protrusion 42 extends along an arc whose diameter is slightly smaller than the inner diameter of the inner peripheral surface 31d of the collar 31, as shown in FIG. 10.
- the driving-side rotator 35 is constructed such that the protrusions 42 can be inserted in the axial direction through the central through hole of the engaging part 34a of the stopper 34.
- a coupling groove 42a extends halfway from an inner peripheral surface of each protrusion 42 in a radially outward direction.
- Each protrusion 42 is circumferentially arranged between the adjacent engaging projections 29b and also between the adjacent rolling elements 32 (roller supports 33c) within the outer ring 31a.
- the cushion member 43 made of the elastomer material is integrally molded to the coupling groove 42a of each protrusion 42.
- the cushion members 43 are connected to the resilient holding portion 38 via through holes 35f (FIGS. 2 and 6) formed at predetermined positions in the resin portion of the driving-side rotator 35.
- a cushion segment 43a is formed in the cushion member 43.
- Each cushion segment 43a extends radially inwardly from the coupling groove 42a of each protrusion 42 and also extends in the circumferential direction. As shown in FIG. 10, a circumferential width of each cushion segment 43a is slightly longer than a circumferential width of the inner peripheral surface of the corresponding protrusion 42.
- each cushion segment 43a engages a first cushion surface 29e, which is formed at a radially inward region of a clockwise side surface of the engaging projection 29b, when the driving-side rotator 35 is rotated to a predetermined position in the counter-clockwise direction (the direction of an arrow X) relative to the driven-side rotator 29.
- One side surface (counter-clockwise side surface) 42b which is formed at a radially inward region of the protrusion 42, engages a first engaging surface 29f, which is formed at a radially outward region of the clockwise side surface of the engaging projection 29b, when the driving-side rotator 35 is further rotated in the counter-clockwise direction (the direction of the arrow X) beyond the predetermined position. Since the cushion segment 43a is deformed in the circumferential direction, the driving-side rotator 35 is allowed to rotate beyond the predetermined position in the counter-clockwise direction (the direction of the arrow X), as shown in FIG. 11.
- each cushion segment 43a engages a second cushion surface 29g, which is formed at a radially inward region of a counter-clockwise side surface of the engaging projection 29b, when the driving-side rotator 35 is rotated to a predetermined position in the clockwise direction (direction of an arrow Y) relative to the driven-side rotator 29.
- each component 32, 42, 29b, 33c is configured in the following manner. That is, each rolling element 32 is placed at the center portion 41a of the corresponding control surface 41 when the one side surface 42b of the corresponding protrusion 42 engages the first engaging surface 29f of the engaging projection 29b, and a first urging surface 42d formed at the radially outward region of the counter-clockwise side surface of the protrusion 42 engages the corresponding roller support 33c (FIG. 11).
- An annular sensor magnet 45 is secured around the shaft portion 35a of the driving-side rotator 35.
- the annular sensor magnet 45 has a plurality of north poles and a plurality of south poles alternately arranged in a circumferential direction of the annular sensor magnet 45.
- a magnetic sensing element 46 such as a Hall element or a magneto-resistive element, is provided in the brush holder 9 near the sensor magnet 45. The magnetic sensing element 46 measures a change in magnetic field during rotation of the sensor magnet 45 to measure a rotational speed of the rotatable shaft 6, which rotates together with the driving-side rotator 35.
- each cushion segment 43a first engages the first cushion surface 29e of the engaging projection 29b before the one side surface 42b of the protrusion 42 engages the first engaging surface 29f of the engaging projection 29b, resulting in reduced shocks at the time of engagement.
- each rolling element 32 is not clamped between the corresponding control surface 41 of the engaging projection 29b and the inner peripheral surface 31d of the collar 31, so that the driven-side rotator 29 is allowed to rotate relative to the collar 31.
- the rotational force of the driving-side rotator 35 is transmitted to the driven-side rotator 29 via the protrusions 42, so that the driven-side rotator 29 is rotated along with the driving-side rotator 35.
- each roller support 33c (support member 33) from the first urging surface 42d of the corresponding protrusion 42 in the same direction (the direction of the arrow X), so that the roller supports 33c (support member 33) are rotated together with the rolling elements 32 in the same direction.
- each rolling element 32 is positioned in the neutral position by the corresponding protrusion 42. At this neutral position, each rolling element 32 is not clamped between the corresponding control surface 41 of the engaging projection 29b and the inner peripheral surface 31d of the collar 31, so that the driven-side rotator 29 is allowed to rotate relative to the collar 31.
- the rotational force of the driving-side rotator 35 is transmitted to the driven-side rotator 29 through the protrusions 42, so that the driven-side rotator 29 is rotated along with the driving-side rotator 35.
- the worm shaft 23 is rotated, and the worm wheel 24 and the output shaft 25 are rotated synchronously with the rotation of the worm shaft 23. Therefore, the window regulator connected to the output shaft 25 is activated to raise or lower the window glass.
- each rolling element 32 moves toward the circumferential end 41c of the control surface 41 of the corresponding engaging projection 29b. Then, when the rolling element 32 reaches the intermediate portion 41d, the rolling element 32 is clamped between the control surface 41 and the inner peripheral surface 31d of the collar 31a (locked state) . Since the outer ring 31a is secured, the driven-side rotator 29 cannot be rotated further, so that the driving-side rotator 35 cannot be rotated by the driven-side rotator 29.
- the window glass which is connected to the output shaft 25, is effectively prevented from moving upward and downward by its own weight or an external force.
- the clutch 20 is assembled. More specifically, with reference to FIG. 9, the driving-side rotator 35 is previously installed to the rotatable shaft 6, and the components of the clutch 20 other than the driving-side rotator 35 are previously installed in the gear housing 21. When the yoke 4 and the gear housing 21 are connected together, the driving-side rotator 35 is placed in a predetermined position relative to the driven-side rotator 29, the support member 33 and the like, and thus the assembly of the clutch 20 is completed.
- the misalignment between the rotational axis of the driving-side rotator 35 and the rotational axis of the rotatable shaft 6 e.g., the tilt of the rotational axis of the rotatable shaft 6 relative to the rotational axis of the driving-side rotator 35, or the radial displacement of the rotational axis of the rotatable shaft 6 relative to the rotational axis of the driving-side rotator 35, which extends parallel to the rotational axis of the rotatable shaft 6
- the misalignment is permitted since the sizes of the corresponding components are selected to allow the loose fit of the connecting portion 6a of the rotatable shaft 6 within the connecting hole 35e of the driving-side rotator 35.
- the application of the relatively large radial loads to the connection between the driving-side rotator 35 and the rotatable shaft 6 is restrained. Furthermore, even if the worm shaft 23 is flexed during its rotation to cause the tilt of the driving-side rotator 35, which in turn results in the misalignment between the rotational axis of the driving-side rotator 35 and the rotational axis of the rotatable shaft 6, the application of the relatively large radial loads to the connection between the driving-side rotator 35 and the rotatable shaft 6 is also effectively restrained. As a result, generation of the relatively large noises and vibrations at the connection between the driving-side rotator 35 and the rotatable shaft 6 during the rotation is effectively restrained.
- the driving-side rotator 35 is resiliently held around the rotatable shaft 6 by the resilient holding portion 38 provided at the connecting hole 35e to restrain the driving-side rotator 35 from falling off the rotatable shaft 6.
- each of the connecting portion 6a of the rotatable shaft 6 and the connecting hole 35e of the driving-side rotator 35 has the diametrically opposing flat wall surfaces.
- the cross section of each of the connecting portion 6a of the rotatable shaft 6 and the connecting hole 35e of the driving-side rotator 35 can have any other shape, such as a polygonal shape (e.g., a quadrangular shape, a hexagonal shape), which allows engagement between the connecting portion 6a of the rotatable shaft 6 and the connecting hole 35e of the driving-side rotator 35 in the rotational direction.
- the connecting portion 6b of the rotatable shaft 6 can have a star shaped cross section. That is, the connecting portion 6b has six radially extending projections, and each projection has a trapezoidal cross section. Also, the connecting hole 35g of the driving-side rotator 35 has a corresponding star shaped cross section (the connecting hole 37d of the metal plate 37 also has the corresponding star shaped cross section). Similar to the above embodiment, the connecting hole 35g of the driving-side rotator 35 and the connecting portion 6b of the rotatable shaft 6 are sized such that the connecting hole 35g and the connecting portion 6b are loosely fitted together (providing a space S between the connecting hole 35g and the connecting portion 6b).
- the connecting portion 6b having the star shaped cross section achieves the rigidity higher than that of the connecting portion 6b having the diametrically opposing flat wall surfaces.
- a cylindrical portion 6c extends continuously from the connecting portion 6b in the rotatable shaft 6.
- the resilient holding portion 38a of the driving-side rotator 35 is closely engaged with and is resiliently held around the cylindrical portion 6c to restrain falling off of the driving-side rotator 35 from the rotatable shaft 6.
- the resilient holding portion 38a is closely engaged with the entire circumference of the cylindrical portion 6c, so that the relatively large resilient holding force can be achieved to restrain the falling off of the driving-side rotator 35 from the rotatable shaft 6.
- a connecting recess 6d can be formed at the distal end surface of the rotatable shaft 6, and a connecting projection 35h for engaging with the connecting recess 6d can be formed in the driving-side rotator 35.
- the connecting recess 6d and the connecting projection 35h can have the diametrically opposed flat wall surfaces or can have the polygonal cross section (e.g., the quadrangular shape, the hexagonal shape) or the star shape cross section to engage with each other in the rotational direction in a manner similar to that described above.
- a central core portion of the connecting projection 35h is made of the resin material.
- a metal plate 39 is secured to an axially middle part of the connecting projection 35h to directly engage with the connecting recess 6d of the rotatable shaft 6 in the rotational direction.
- the metal plate 39 has a cross sectional shape, which corresponds to that of the connecting recess 6d of the rotatable shaft 6. Similar to the above embodiment, the metal plate 39 and the connecting recess 6d are sized such that the metal plate 39 is loosely fitted within the connecting recess 6d of the rotatable shaft 6, thereby forming a space S therebetween.
- a resilient holding portion 40 is integrally formed around the connecting projection 35h except the metal plate 39.
- the resilient holding portion 40 is closely engaged with an inner wall of the connecting recess 6d of the rotatable shaft 6 to resiliently hold the driving-side rotator 35 around the rotatable shaft 6 to restrain the driving-side rotator 35 from falling off the rotatable shaft 6 at the time of assembly of the motor 1.
- the modification of the shape of the metal plate 37 is not limited to the above metal plate 39, and metal plate 37 can be further modified in any appropriate form.
- the metal plate 37 is insert molded within the driving-side rotator 35.
- the metal plate 37 can be separately manufactured from the driving-side rotator 35 and can be assembled to the driving-side rotator 35.
- the resin material of the driving-side rotator 35 has an enough rigidity, the metal plate 37 can be eliminated, as shown in FIG. 16.
- the shape and the material of the resilient holding portion 38 of the above embodiment are not limited to ones described above and can be changed to any ones.
- the resilient holding portion 38 is integrally molded in the driving-side rotator 35 in the above embodiment.
- the resilient holding portion 38 can be manufactured separately from the driving-side rotator 35 and can be assembled to the driving-side rotator 35.
- a resilient holding portion can be provided in the rotatable shaft 6. Also, if there is no possibility for the driving-side rotator 35 to fall off the rotatable shaft 6 during the assembly (for example, in a case where the connecting portion 6a is upwardly oriented, and the driving-side rotator 35 is installed to the upwardly oriented connecting portion 6a), the resilient holding portion 38 can be eliminated.
- the driven-side rotator 29 is integrally formed with the worm shaft 23.
- the driven-side rotator 29 can be formed separately from the worm shaft 23 and can be assembled to the worm shaft 23.
- the positioning means for positioning the brush holder 9 and the gear housing 21 relative to each other includes the positioning holes 9d and the positioning projections 21n.
- the shapes, the positions and the number of the positioning holes 9d and the positioning projections 21n can be changed to any appropriate ones.
- the positioning holes 9d are provided in the brush holder 9, and the positioning projections 21n are provided in the gear housing 21.
- the positioning projections can be provided in the brush holder 9, and the positioning holes can be provided in the gear housing 21.
- the number of the positioning holes 9d is two, and the number of the positioning projections 21n is two.
- the number of the positioning projections 21n is two.
- only one positioning hole 9d and the corresponding one positioning projection 21n can be provided.
- more than two positioning holes 9d and the corresponding number of the positioning projections 21n can be provided.
- each positioning hole 9d has the circular cross section, and each positioning projection 21n has the cylindrical shape.
- each positioning hole 9d can have a polygonal cross section, and each positioning projection 21n can have a polygonal projection.
- the positioning projections 21n are symmetrically arranged about the rotatable shaft 6 at the diagonal corners, and the positioning holes 9d are also symmetrically arranged about the rotatable shaft 6 in opposed relationship to the corresponding positioning projections 21n.
- the positioning projections 21n can be symmetrically arranged about the rotatable shaft 6 at any positions generally along the longitudinal direction of the cross section of the elongated open end of the housing 21, and the positioning holes 9d can be also symmetrically arranged about the rotatable shaft 6 in opposed relationship to the corresponding positioning projections 21n.
- the structure of the clutch 20 of the above embodiment can be modified in any appropriate manner.
- the clutch 20 is constructed such that each rolling element 32 is clamped between the corresponding control surface 41 of the driven-side rotator 29 and the inner peripheral surface 31d of the collar 31 to lock the driven-side rotator 29, thereby preventing transmission of the rotational force from the load side to the driving-side rotator 35 through the driven-side rotator 29.
- the clutch can be constructed such that the rotation of the driven-side rotator 29 is allowed while predetermined frictional force is applied to the driven-side rotator 29 from the inner peripheral surface 31d of the collar 31 and each rolling element 32, which is clamped between the corresponding control surface 41 of the driven-side rotator 29 and the inner peripheral surface 31d of the collar 31.
- the clutch 20 is used as the coupling means for drivingly coupling the rotatable shaft 6 to the worm shaft 23.
- any other coupling means for drivingly coupling the rotatable shaft 6 to the worm shaft 23 can be used.
- the structures of the motor main body 2 and the speed reducing unit 3 of the above embodiment can be modified in any appropriate manner.
- the motor 1 is used as the drive source of the power window system.
- the motor 1 can be used as a drive source of any other devices and systems.
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Abstract
Description
- The present invention relates to a motor including a clutch, which couples a rotatable shaft of a rotor to a worm shaft.
- With reference to FIG. 17, one previously proposed motor used, for example, in a power window system includes a motor
main body 52, aspeed reducing unit 54 and aclutch 55. The motormain body 52 rotates arotatable shaft 51. Thespeed reducing unit 54 includes aworm shaft 53 and transmits rotational driving force of theworm shaft 53 to a load side (e.g., a door window glass side of the power window system). Theclutch 55 is placed between therotatable shaft 51 and theworm shaft 53. - With reference to FIG. 18, the
clutch 55 includes a driving-side rotator 61, a driven-side rotator 62, acollar 63 androlling elements 64. The driving-side rotator 61 is connected to a distal end of therotatable shaft 51 to rotate integrally therewith. The driven-side rotator 62 is integrally connected to a base end of theworm shaft 53. Thecollar 63 surrounds both the driving-side rotator 61 and the driven-side rotator 62 and is secured to agear housing 56 of thespeed reducing unit 54. Therolling elements 64 are arranged between the driven-side rotator 62 and thecollar 63. In theclutch 55, when the driving-side rotator 61 is rotated, eachrolling element 64 is rotated together with the driving-side rotator 61 without being clumped between acorresponding control surface 62a of the driven-side rotator 62 and an innerperipheral surface 63a of thecollar 63, and the driven-side rotator 62 is engaged with and is rotated by the driving-side rotator 61 in a rotational direction. On the other hand, when rotational force is applied to the driven-side rotator 62 from the load side (worm shaft 53 side) to rotate the driven-side rotator 62, eachrolling element 64 is clamped between thecorresponding control surface 62a of the driven-side rotator 62 and the innerperipheral surface 63a of thecollar 63 to restrain the rotation of the driven-side rotator 62. - Thus, when the
rotatable shaft 51 is rotated by the motormain body 52, the rotational driving force of therotatable shaft 51 is transmitted to theworm shaft 53 through theclutch 55 to raise or lower the window glass. On the other hand, when load (e.g., weight of the window glass or vibrations of the window glass) is downwardly applied to the window glass to apply rotational force to theworm shaft 53, the rotation of theworm shaft 53 is restrained by theclutch 55 to restrain the unexpected downward movement of the window glass. - In order to properly operate the
clutch 55, the driving-side rotator 61 and the driven-side rotator 62 are installed such that a rotational axis of the driving-side rotator 61 is aligned with a rotational axis of the driven-side rotator 62. Furthermore, a connectinghole 61a is formed in a central portion of the driving-side rotator 61 to extend in an axial direction. A connectingportion 51a formed in a distal end of therotatable shaft 51 is press fitted into the connectinghole 61a of the driving-side rotator 61, so that therotatable shaft 51 and the driving-side rotator 61 are connected to each other to rotate together. Thus, it is required to assemble the motor such that the central axis of the driving-side rotator 61 (connectinghole 61a) and the central axis of therotatable shaft 51 are aligned with each other. - However, for example, due to a manufacturing error of each corresponding connecting portion, misalignment between the rotational axis of the driving-
side rotator 61 and the rotational axis of the rotatable shaft 51 (e.g., tilt of the rotational axis of therotatable shaft 51 relative to the rotational axis of the driving-side rotator 61, or radial displacement of the rotational axis of therotatable shaft 51 relative to the rotational axis of the driving-side rotator 61, which extends parallel to the rotational axis of the rotatable shaft 51) can occur. When the misalignment occurs, relatively large radial loads are applied to the connection between the driving-side rotator 61 and therotatable shaft 51. If the driving-side rotator 61 and therotatable shaft 51 are rotated at this state, relatively large noises and vibrations are generated at the connection between the driving-side rotator 61 and therotatable shaft 51. - The present invention addresses the above disadvantages. Thus, it is an objective of the present invention to provide a motor capable of reducing generation of noises and vibrations at a connection between a rotatable shaft of a rotor and a worm shaft.
- To achieve the objective of the present invention, there is provided a motor including a motor main body, a speed reducing unit and a coupling means. The motor main body includes a rotatable shaft and rotates the rotatable shaft. The speed reducing unit is connected to the motor main body and includes a worm shaft. The worm shaft is substantially coaxial with the rotatable shaft. The coupling means couples the rotatable shaft with the worm shaft. The coupling means includes a driving-side rotator and a driven-side rotator. The driving-side rotator is connected with the rotatable shaft to rotate integrally with the rotatable shaft. The driven-side rotator is connected with the worm shaft to rotate integrally with the worm shaft and is engageable with the driving-side rotator in a rotational direction. The rotatable shaft includes a connecting portion. The driving-side rotator includes a connecting portion, which is loosely fitted with the connecting portion of the rotatable shaft and is engageable with the connecting portion of the rotatable shaft in the rotational direction to rotate integrally with the connecting portion of the rotatable shaft.
- To achieve the objective of the present invention, there is also provided a motor including a motor main body, a brush holder, a speed reducing unit, a coupling means and a positioning means. The motor main body includes a yoke housing. The yoke housing rotatably receives an armature, which includes a rotatable shaft and a commutator. The brush holder is placed in an opening of the yoke housing. The brush holder holds a plurality of brushes in sliding contact with the commutator and includes a bearing, which rotatably supports the rotatable shaft. The speed reducing unit includes a gear housing connected to the yoke housing in such a manner that the brush holder is arranged between the opening of the gear housing and an opening of the yoke housing. The gear housing rotatably receives a worm shaft, which is substantially coaxial with the rotatable shaft. The coupling means couples the rotatable shaft with the worm shaft. The positioning means is placed between the brush holder and the gear housing for positioning the brush holder and the gear housing relative to each other.
- The invention, together with additional objectives, features and advantages thereof, will be best understood from the following description, the appended claims and the accompanying drawings in which:
- FIG. 1 is a cross-sectional view of a motor according to an embodiment of the present invention;
- FIG. 2 is an enlarged partial cross sectional view of FIG. 1;
- FIG. 3 is another enlarged partial cross sectional view of FIG. 1;
- FIG. 4 is an exploded view showing a clutch of the motor;
- FIG. 5 is a plan view of a gear housing of the motor;
- FIG. 6A is a plan view of a driving-side rotator of the motor;
- FIG. 6B is a cross sectional view taken along line VIB-VIB in FIG. 6A;
- FIG. 6C is a bottom view of the driving-side rotator shown in FIGS. 6A and 6B;
- FIG. 7A is another plan view of the driving-side rotator;
- FIG. 7B is a cross-sectional view taken along line VIIB-VIIB in FIG. 7A;
- FIG. 7C is a bottom view of the driving-side rotator shown in FIGS. 7A and 7B;
- FIG. 8 is a perspective view of a metal place of the motor;
- FIG. 9 is a schematic partial cross sectional view showing assembly of the clutch of the motor;
- FIG. 10 is a cross sectional view taken along line X-X in FIG. 2;
- FIG. 11 is a schematic cross sectional view showing operation of the clutch;
- FIG. 12 is another schematic cross sectional view showing the operation of the clutch;
- FIG. 13 is a partial enlarged cross sectional view showing a modification of the motor;
- FIG. 14 is a partial perspective view of a rotatable shaft of the motor shown in FIG. 13;
- FIG. 15A is an enlarged cross sectional view showing another modification of the motor;
- FIG. 15B is an enlarged view of a section XVB in FIG. 15A;
- FIG. 16 is an enlarged cross sectional view showing a further modification of the motor;
- FIG. 17 is a cross sectional view of a previously proposed motor; and
- FIG. 18 is a partial enlarged view of the motor shown in FIG. 17.
-
- An embodiment of the present invention will be described with reference to the accompanying drawings.
- FIG. 1 is a schematic cross sectional view of a
motor 1 used as a drive source of a power window system according to the present embodiment. Themotor 1 includes a flat motor main body 2, aspeed reducing unit 3 and a clutch (coupling means) 20. - As shown in FIG. 1, the motor main body 2 includes a yoke housing (hereinafter, simply referred to as a yoke) 4, a couple of
magnets 5, arotatable shaft 6, anarmature 7, acommutator 8, abrush holder 9 and brushes 10. - The
yoke 4 is shaped into a flat cup shape. Themagnets 5 are secured to an inner peripheral surface of theyoke 4 and are opposed to each other. Thearmature 7 is arranged radially inward of themagnets 5 in theyoke 4. Thearmature 7 has therotatable shaft 6. A base end of therotatable shaft 6 is rotatably supported by a bearing 11 arranged at the bottom center of theyoke 4. Thecommutator 8 is secured to a predetermined distal end portion of therotatable shaft 6. As shown in FIGS. 2 to 4, a connectingportion 6a, which has diametrically opposing flat outer wall surfaces, is formed at the distal end of therotatable shaft 6. - At an open end (opening) of the
yoke 4, twoflanges 4a are formed to extend outwardly in a longitudinal direction of an elongated lateral cross-section of theyoke 4. - Furthermore, the
brush holder 9 is received within and secured to the open end of theyoke 4. Thebrush holder 9 includes a holdermain body 9a and aconnector 9b. The holdermain body 9a is configured to substantially cover the open end of theyoke 4. Theconnector 9b is formed integrally with the holdermain body 9a and protrudes outwardly from the holdermain body 9a in a radial direction of theyoke 4. Thebrushes 10 are supported by the holdermain body 9a. Thebrushes 10 are electrically connected to theconnector 9b through electrical lines (not shown) and are slidably engaged with thecommutator 8. Abearing 12 is supported at the center of the holdermain body 9a. An intermediate portion of therotatable shaft 6, which is located between thecommutator 8 and the connectingportion 6a, is rotatably supported by thebearing 12. With reference to FIG. 1, aclamp portion 9c extends along an entire outer peripheral edge of the holdermain body 9a. Theclamp portion 9c is clamped between the open end of theyoke 4 and an open end (opening) of agear housing 21, which will be described below, along substantially an entire inner perimeter of the open end of theyoke 4. Theclamp portion 9c is covered with an elastic seal member such that the seal member prevents penetration of water through the connection between theyoke 4 and thegear housing 21 when theclamp portion 9c is clamped therebetween. Furthermore, on thegear housing 21 side of the holdermain body 9a, a couple ofcircular positioning holes 9d are provided radially inward of theclamp portion 9c at opposite diagonal corners, respectively, of the holdermain body 9a. The positioning holes 9d are symmetrically arranged with respect the rotatable shaft 6 (i.e., eachpositioning hole 9d is equally spaced from the rotatable shaft 6) and penetrate through the holdermain body 9a. - Electric power is supplied to the
brushes 10 from an external power source through theconnector 9b. When the electric power is supplied from the external power source to coil windings wound around thearmature 7 through thebrushes 10 and thecommutator 8, the armature 7 (rotatable shaft 6), i.e., the motor main body 2 is rotated. - The
speed reducing unit 3 includes thegear housing 21,bearings worm shaft 23, aworm wheel 24 and anoutput shaft 25. - The
gear housing 21 is made of a resin material. An open end (this open end is the top side in FIG. 1 and will be hereinafter referred as the top open end) of thegear housing 21, to which the motor main body 2 is secured, has a flat elongated cross section that corresponds with the open end of theyoke 4. With reference to FIGS. 4 and 5, at the top open end of thegear housing 21, there is formed anengaging recess 21a within which the holdermain body 9a of thebrush holder 9 is received. Securingportions 21b are formed around the engagingrecess 21a in the top open end of thegear housing 21. Theflanges 4a of theyoke 4 are secured to the securingportions 21b to secure theyoke 4 to thegear housing 21. Threescrew receiving holes 21c are formed at three predetermined positions in the securingportions 21b. A nut (not shown) is received in eachscrew receiving hole 21c. Thegear housing 21, which has the holdermain body 9a securely fitted to theengaging recess 21a, is securely connected to theyoke 4 by inserting three screws 13 (only one is shown in FIG. 1) into thescrew receiving holes 21c through screw receiving holes (not shown) formed in theflanges 4a of theyoke 4 and threadably tightening thescrews 13 into the nuts received in thescrew receiving holes 21c. - The
gear housing 21 has arecess 21d that is recessed from a base of theengaging recess 21a at the center thereof. Therecess 21d is elongated in a longitudinal direction of an elongated cross section of theengaging recess 21a. Thegear housing 21 further includes a clutch receivingcircular recess 21e and a wormshaft receiving portion 21f (FIGS. 2 and 3). Theclutch receiving recess 21e is further recessed from a base of therecess 21d at the center thereof. The wormshaft receiving portion 21f is further recessed from a base of theclutch receiving recess 21e at the center thereof in the axial direction of therotatable shaft 6. Thegear housing 21 further includes awheel receiving portion 21g. Thewheel receiving portion 21g is communicated with the wormshaft receiving portion 21f in a direction perpendicular to an axial direction of the wormshaft receiving portion 21f at an axially middle portion of the wormshaft receiving portion 21f (i.e., thewheel receiving portion 21g is located on the right side of the wormshaft receiving portion 21f in FIG. 1). - With reference to FIG. 4, an annular
flange engaging recess 21h is formed at an open end of theclutch receiving recess 21e. Opposed engaging recesses 21i extend continuously from the engagingrecess 21h in the longitudinal direction of the elongated lateral cross-section of therecess 21d. - At the base of the
recess 21d, twobase portions 21j are formed. Eachbase portion 21j is formed to surround the corresponding engaging recess 21i. That is, eachbase portion 21j is horseshoe-shaped and has a peripheral wall surface that is continuous with a wall surface of the engaging recess 21i. Eachbase portion 21j has opposite ends that are located adjacent to the lateral end sides of the lateral cross-section of therecess 21d, respectively. Cylindrical engagingprojections 21k are formed in top surfaces of the opposite ends, respectively, of eachbase portion 21j. - With reference to FIGS. 2 and 3, a
bearing support portion 211 protrudes from the base of theclutch receiving recess 21e. The cylindricalbearing support portion 211 is flexible in a direction perpendicular to the axial direction. Thebearing support portion 211 is shaped into a generally cylindrical shape and has an inner diameter, which is larger than an inner diameter of the wormshaft receiving portion 21f, and an outer diameter, which is smaller than an inner diameter of theclutch receiving recess 21e. Furthermore, thebearing support portion 211 generally extends to the center of theclutch receiving recess 21e in the axial direction. As shown in FIGS. 2, 3 and 5, eightribs 21m are arranged at equal angular intervals (45 degrees) along an outer peripheral surface of thebearing support portion 211 at the base end thereof. Theribs 21m are connected to an inner peripheral surface of theclutch receiving recess 21e. - The
bearings bearing 22a is received in thebearing support portion 211. An inner diameter of thebearing 22a is smaller than the inner diameter of the wormshaft receiving portion 21f. Thebearing 22b is engaged with an inner peripheral surface of a base portion (bottom side in FIG. 1) of the wormshaft receiving portion 21f. - A couple of
cylindrical positioning projections 21n are provided in the base of therecess 21d of thegear housing 21 in opposed relationship to thepositioning holes 9d, respectively, of thebrush holder 9. Eachpositioning projection 21n extends in the axial direction and is engaged with thecorresponding positioning hole 9d. When thepositioning projections 21n are engaged with thepositioning holes 9d, respectively, thebrush holder 9 and thegear housing 21 are positioned relative to each other. That is, in the present embodiment, thepositioning projections 21n and thepositioning holes 9d constitute a positioning means. As described above, theclamp portion 9c of thebrush holder 9 is received in theengaging recess 21a of thegear housing 21. However, theclamp portion 9c is covered with the elastic seal member, so that theclamp portion 9c cannot achieve accurate positioning. Thus, in the present embodiment, thebrush holder 9 and thegear housing 21 are positioned relative to each other by thepositioning projections 21n of thegear housing 21 and thepositioning holes 9d of thebrush holder 9. As a result, accumulation of errors between therotatable shaft 6 and theworm shaft 23 is reduced, so that misalignment between a rotational axis of therotatable shaft 6 and a rotational axis of the worm shaft 23 (e.g., tilt of the rotational axis of therotatable shaft 6 relative to the rotational axis of theworm shaft 23, or radial displacement of the rotational axis of therotatable shaft 6 relative to the rotational axis of theworm shaft 23, which extends parallel to the rotational axis of the rotatable shaft 6) is more effectively reduced. - The
worm shaft 23 is made of a metal material and includes a worm shaftmain body 28 and a driven-side rotator 29 that is integrally formed with the worm shaftmain body 28 on a motor main body 2 side of the worm shaftmain body 28, as shown in FIG. 4. The worm shaftmain body 28 has aworm 28a in the axially middle part thereof. Furthermore, the worm shaftmain body 28 is rotatably supported by thebearings shaft receiving portion 21f. Acontact member 26 is provided in a motor main body 2 side end surface (end surface of the driven-side rotator 29) of theworm shaft 23 at a position where a ball 36 (described below) contacts theworm shaft 23. Thecontact member 26 makes a point contact with theball 36. Thus, thecontact member 26 is made of a metal material (hardened metal material) having rigidity higher than the rest of theworm shaft 23 to restrain excessive wearing of the contact portion of thecontact member 26, which contacts theball 36. - The
worm wheel 24 is meshed with theworm 28a and is received within thewheel receiving portion 21g in such a manner that theworm wheel 24 is allowed to rotate about its rotational axial, which extends in a direction (direction perpendicular to the drawing surface in FIG. 1) perpendicular to theworm shaft 23. Theoutput shaft 25 is connected to theworm wheel 24 in such a manner that theoutput shaft 25 coaxially rotates with theworm wheel 24 when theworm wheel 24 is rotated. Theoutput shaft 25 is drivingly connected to a known window regulator (not shown) for raising and lowering a window glass. - The
rotatable shaft 6 is connected to theworm shaft 23 via the clutch 20. As shown in FIGS. 2 to 4, the clutch 20 includes the driven-side rotator 29, acollar 31, a plurality (three in this embodiment) of rollingelements 32, asupport member 33, astopper 34, a driving-side rotator 35 and theball 36. FIG. 3 shows the structure around therotatable shaft 6, which is rotated 90 degrees with respect to therotatable shaft 6 shown in FIG. 2. FIG. 2 is a cross-sectional view corresponding to FIG. 6B, which is a cross-sectional view taken along line VIB-VIB in FIG. 6A (i.e., FIG 2 also shows the cross-sectional view taken along line VIB-VIB in FIG. 6A). FIG. 3 is a cross-sectional view corresponding to FIG. 7B, which is a cross-sectional view taken along line VIIB-VIIB in FIG. 7A (i.e., FIG 3 also shows the cross-sectional view taken along line VIIB-VIIB in FIG. 7A). - The
collar 31 includes a cylindricalouter ring 31a, anannular flange portion 31b and a couple of engagingportions 31c. Theannular flange portion 31b extends radially outwardly from one end (upper end in FIGS. 2 to 4) of the cylindricalouter ring 31a. The engagingportions 31c are angularly spaced 180 degrees apart from each other and protrude radially outwardly from theflange portion 31b. Theouter ring 31a of thecollar 31 is fitted within theclutch receiving portion 21e. Theflange portion 31b of thecollar 31 is fitted to theflange engaging recess 21h. The engagingportions 31c are fitted within the engaging recesses 21i, respectively, so that rotation of thecollar 31 is prevented. The other end (lower end in FIGS. 2 and 3) of theouter ring 31a of thecollar 31 is inserted to a point near a distal end of the bearing support portion 211 (top end in FIGS. 2 and 3) and does not interfere with the flexing of thebearing support portion 211. The driven-side rotator 29 is positioned inward of theouter ring 31a. - As shown in FIG. 4, the driven-
side rotator 29 includes ashaft portion 29a and threeengaging projections 29b. Theshaft portion 29a extends coaxially from a base end of the worm shaftmain body 28 on the motor main body 2 side (rotatable shaft 6 side). The engagingprojections 29b extend radially outwardly from theshaft portion 29a and are arranged at substantially equal angular intervals (about 120 degrees). Each engagingprojection 29b has a progressively increasing circumferential width that increases toward a radially outer end thereof. As shown in FIG. 10, which is a cross sectional view taken along line X-X in FIG. 2, a radially outer surface of each engagingprojection 29b constitutes acontrol surface 41. Eachcontrol surface 41 is spaced from an innerperipheral surface 31d of theouter ring 31a of thecollar 31 for a distance that varies in a rotational direction or circumferential direction. Eachcontrol surface 41 of the present embodiment is a flat surface that is spaced from thecollar 31 for a distance that decreases toward each circumferential end of thecontrol surface 41. As shown in FIG. 4, the driven-side rotator 29 includes reinforcingribs 29c for reinforcing the engagingprojections 29b. Each reinforcingrib 29c is formed to connect circumferentially opposed lateral surfaces of each circumferentially adjacent pair of engagingprojections 29b. - Each rolling
element 32 is made of a resin material and is shaped into a generally cylindrical shape. Furthermore, as shown in FIG. 10, each rollingelement 32 is arranged between thecontrol surface 41 of the corresponding engagingprojection 29b and the innerperipheral surface 31d of thecollar 31. An outer diameter of the rollingelement 32 is smaller than a distance between a center portion (circumferential center) 41a of thecontrol surface 41 and the innerperipheral surface 31d of thecollar 31 but is longer than a distance between each of end portions (circumferential ends) 41b, 41c of thecontrol surface 41 and the innerperipheral surface 31d of thecollar 31. That is, the outer diameter of the rollingelement 32 is equal to a distance between the innerperipheral surface 31d of thecollar 31 and eachintermediate portion 41d located between thecenter portion 41a and eachcircumferential end - The
support member 33 rotatably supports the rollingelements 32 in such a manner that the rollingelements 32 are arranged parallel to one another at substantially equal angular intervals. More specifically, with reference to FIGS. 2 to 4, thesupport member 33 is made of a resin material and includes aring 33a, threeinward protrusions 33b, three pairs of roller supports 33c and threeconnectors 33d. Thering 33a is formed into an annular shape having an outer diameter larger than that of theouter ring 31a. Theinward protrusions 33b extend radially inwardly from an inner peripheral surface of thering 33a and are circumferentially arranged at substantially equal angular intervals. Each pair of roller supports 33c is provided to eachinward protrusion 33b. The paired roller supports 33c extend axially from circumferential ends, respectively, of the correspondinginward protrusion 33b at a radially inward region of theinward protrusion 33b. Eachconnector 33d is formed into an arcuate shape that connects oneroller support 33c of one pair to the followingroller support 33c of the next pair. In each pair of roller supports 33c, two circumferentially opposing engagingprojections 33e are formed in distal ends of the roller supports 33c. Each rollingelement 32 is held between the paired roller supports 33c and also between theinward protrusion 33b and the opposing engagingprojections 33e in such a manner that the rollingelement 32 is immovably held with respect to thering 33a in a circumferential direction and also in an axial direction. Thesupport member 33, which holds the rollingelements 32 in the above-described manner, is positioned such that eachroller support 33c is inserted into the inside of theouter ring 31a to position each rollingelement 32 between thecorresponding control surface 41 and the innerperipheral surface 31d of thecollar 31, and thering 33a abuts against theflange portion 31b in the axial direction. - The
stopper 34 is made of a metal plate having a generally uniform thickness throughout it. Thestopper 34 includes an annularengaging part 34a and a pair ofextended parts 34b. An inner diameter of theengaging part 34a is substantially equal to the inner diameter of thering 33a of thesupport member 33. Theextended parts 34b are angularly spaced 180 degrees apart from each other and protrude radially outwardly from theengaging part 34a. With reference to FIGS. 2 and 3, an inner diameter and the outer diameter of theengaging part 34a are substantially the same as the inner diameter and the outer diameter, respectively, of the cylindricalouter ring 31a of thecollar 31. Eachextended part 34b includes securingportions 34c. The securingportions 34c are provided at four corners, respectively, of thestopper 34 in such a manner that positions of the securingportions 34c correspond to the positions of the corresponding engagingprojections 21k, respectively, of thegear housing 21. The engagingprojections 21k are inserted into the securingportions 34c, respectively, to secure thestopper 34 to thegear housing 21. Theengaging part 34a of thestopper 34 is placed over thering 33a of the support member 33 (placed at the top side in FIG. 1). Once thering 33a of thesupport member 33 abuts against theengaging part 34a of thestopper 34, thestopper 34 prevents axial movement of each rollingelement 32 in cooperation with thesupport member 33. With reference to FIGS. 2 to 4, eachextended part 34b has a limitingportion 34d at the center thereof. Each limitingportion 34d is formed by cutting the corresponding center portion of theextended part 34b and then bending it obliquely. A distal end of each limitingportion 34d abuts against the corresponding engagingportion 31c of thecollar 31 to restrain the axial movement of thecollar 31. - The driving-
side rotator 35 includes ashaft portion 35a, adisk portion 35b and aball holding portion 35c. Thedisk portion 35b has an outer diameter larger than that of theshaft portion 35a. Theball holding portion 35c is formed in the center of thedisk portion 35b. Aball receiving recess 35d for holding theball 36 is formed in theball holding portion 35c. Theball 36 is held in theball receiving recess 35d in such a manner that theball 36 partially protrudes from theball receiving recess 35d in both axial directions and is engaged with an end surface of therotatable shaft 6 at one axial end and with the end surface of the worm shaft 23 (contact member 26) at the opposite axial end. Similar to thecontact member 26, theball 36 is made of a hardened metal material to achieve the higher rigidity. - A connecting
hole 35e axially extends through the axial center of the driving-side rotator 35 from a base end (top end in FIGS. 2 and 3) of theshaft portion 35a to theball holding portion 35c. The connectinghole 35e acts as a connecting portion and has two diametrically opposing flat inner wall surfaces. The connectingportion 6a of therotatable shaft 6 is loosely fitted within the connectinghole 35e. That is, a size of the connectinghole 35e is larger than a size of the connectingportion 6a of therotatable shaft 6 by a predetermined amount, so that a space S is formed between the connectinghole 35e and the connectingportion 6a of therotatable shaft 6. The driving-side rotator 35 is drivingly connected to therotatable shaft 6 to rotate together by loosely fitting the connectingportion 6a of therotatable shaft 6 within theconnection hole 35e. - Since the connecting
portion 6a of therotatable shaft 6 is loosely fitted within the connectinghole 35e, a certain amount of misalignment between the rotational axis of the driving-side rotator 35 and the rotational axis of the rotatable shaft 6 (e.g., tilt of the rotational axis of therotatable shaft 6 relative to the rotational axis of the driving-side rotator 35, or radial displacement of the rotational axis of therotatable shaft 6 relative to the rotational axis of the driving-side rotator 35, which extends parallel to the rotational axis of the rotatable shaft 6) is permitted at the assembly of the motor. Thus, application of relatively large radial loads to the connection between the driving-side rotator 35 and therotatable shaft 6 is restrained. Furthermore, even when theworm shaft 23 is flexed during its rotation to cause tilt of the driving-side rotator 35, which in turn results in the misalignment between the rotational axis of the driving-side rotator 35 and the rotational axis of therotatable shaft 6, application of the relatively large radial loads to the connection between the driving-side rotator 35 and therotatable shaft 6 is also effectively restrained. As a result, generation of noises and vibrations at the connection between the driving-side rotator 35 and therotatable shaft 6 during the rotation is effectively restrained. When the rotational axis of therotatable shaft 6 is tilted relative to the rotational axis of the driving-side rotator 35, the end surface of therotatable shaft 6 makes the point contact with theball 36, so that therotatable shaft 6 can easily follow the driving-side rotator 35. - The driving-
side rotator 35 of the present embodiment is formed by insert molding ametal plate 37 within a resin body having a shape generally corresponding to the shape of the driving-side rotator 35. Then, an elastomer material is integrally molded to the resin body to form a resilient holdingportion 38 andcushion members 43, which will be described later. - As shown in FIG. 8, the
metal plate 37 has adisk portion 37a and threearm portions 37b. Thedisk portion 37a of themetal plate 37 is insert molded within thedisk portion 35b of the driving-side rotator 35. Eacharm portion 37b extends radially outwardly from thedisk portion 37a to a correspondingprotrusion 42, which will be described later. Themetal plate 37 is inserted within the driving-side rotator 35b to improve the rigidity of the driving-side rotator 35, particularly the rigidity of eachprotrusion 42, which is engaged with the driven-side rotator 29 to transmit driving force to the driven-side rotator 29, and also the rigidity of the connectinghole 35e, which is connected with the connectingportion 6a of therotatable shaft 6 to transmit driving force from therotatable shaft 6 to the driving-side rotator 35. - A connecting
hole 37c is formed in the center of thedisk portion 37a of themetal plate 37. The connectinghole 37c acts as an engaging hole and is disposed in the connectinghole 35e. A cross sectional shape of the connectinghole 37c substantially coincides with that of the connectinghole 35e. An inner peripheral surface of the connectinghole 37c is flushed with an inner peripheral surface of the connectinghole 35e. The driving-side rotator 35 is molded by pouring a resin material in a molding die (not shown). In this process, themetal plate 37 is previously positioned in the molding die before the resin material is poured into the molding die. The connectinghole 37c is used to position themetal plate 37 in the molding die. - The connecting
hole 35e, in which the connectinghole 37c of themetal plate 37 is disposed, is engaged with the connectingportion 6a of therotatable shaft 6 in the rotational direction. Although the axial size of the connectinghole 35e is relatively small, the rigidity of the connectinghole 35e is increased by themetal plate 37. Thus, the rotational driving force transmitted from therotatable shaft 6 can be effectively conducted to the driving-side rotator 35 while the axial size of the driving-side rotator 35 is minimized. Furthermore, because of the relatively short axial size of the connectinghole 35e, an allowed tilt angle of therotatable shaft 6 relative to the driving-side rotator 35 is increased. Thus, even when the tilt angle of therotatable shaft 6 becomes relatively large, it is relatively easy to counteract this. - The resilient holding
portion 38, which is made of a resilient elastomer material, is integrally molded to the driving-side rotator 35 such that the resilient holdingportion 38 continuously extends from an open end of the connectinghole 35e. A space between the opposite inner wall surfaces located at an open end (top end in FIG. 6B) of theshaft portion 35a, which has the integrally molded resilient holdingportion 38, is larger than that of the connectinghole 35e. As shown in FIGS. 6A to 7C, a space between the opposite inner wall surfaces (left and right wall surfaces in FIG. 6B) of the resilient holdingportion 38 located adjacent to the opposite flat inner wall surfaces (left and right wall surfaces in FIG. 6B) of the connectinghole 37c of themetal plate 37 is smaller than a space between the opposite flat inner wall surfaces of the connectinghole 37c of themetal plate 37. Thus, the resilient holdingportion 38 is resiliently engaged with the flat outer wall surfaces of the connectingportion 6a of therotatable shaft 6. As a result, when the driving-side rotator 35 is installed to therotatable shaft 6 during the assembly of themotor 1, the driving-side rotator 35 is resiliently held around therotatable shaft 6 by the resilient holdingportion 38 and thus is restrained from falling off therotatable shaft 6, thereby accelerating the assembling operation of themotor 1. As described above, even if the misalignment between the rotational axis of the driving-side rotator 35 and the rotational axis of therotatable shaft 6 occurs, the resilient holdingportion 38 is resiliently deformed without any adverse effects. - As shown in FIGS. 4 and 6A to 7C, a plurality (three in this embodiment) of generally fan-shaped
protrusions 42, which extend radially outwardly and also extend in the axial direction, are arranged at substantially equal angular intervals on the distal end side (bottom side in FIG. 2) of thedisk portion 35b of the driving-side rotator 35. Eachprotrusion 42 includes an arcuate outer surface, which circumferentially extends along the innerperipheral surface 31d of thecollar 31. The arcuate outer surface of eachprotrusion 42 extends along an arc whose diameter is slightly smaller than the inner diameter of the innerperipheral surface 31d of thecollar 31, as shown in FIG. 10. That is, the driving-side rotator 35 is constructed such that theprotrusions 42 can be inserted in the axial direction through the central through hole of theengaging part 34a of thestopper 34. In eachprotrusion 42, acoupling groove 42a (FIG. 10) extends halfway from an inner peripheral surface of eachprotrusion 42 in a radially outward direction. Eachprotrusion 42 is circumferentially arranged between the adjacentengaging projections 29b and also between the adjacent rolling elements 32 (roller supports 33c) within theouter ring 31a. - The
cushion member 43 made of the elastomer material is integrally molded to thecoupling groove 42a of eachprotrusion 42. Thecushion members 43 are connected to the resilient holdingportion 38 via throughholes 35f (FIGS. 2 and 6) formed at predetermined positions in the resin portion of the driving-side rotator 35. Acushion segment 43a is formed in thecushion member 43. Eachcushion segment 43a extends radially inwardly from thecoupling groove 42a of eachprotrusion 42 and also extends in the circumferential direction. As shown in FIG. 10, a circumferential width of eachcushion segment 43a is slightly longer than a circumferential width of the inner peripheral surface of the correspondingprotrusion 42. - One side surface (counter-clockwise side surface) 43b of each
cushion segment 43a engages afirst cushion surface 29e, which is formed at a radially inward region of a clockwise side surface of the engagingprojection 29b, when the driving-side rotator 35 is rotated to a predetermined position in the counter-clockwise direction (the direction of an arrow X) relative to the driven-side rotator 29. One side surface (counter-clockwise side surface) 42b, which is formed at a radially inward region of theprotrusion 42, engages a firstengaging surface 29f, which is formed at a radially outward region of the clockwise side surface of the engagingprojection 29b, when the driving-side rotator 35 is further rotated in the counter-clockwise direction (the direction of the arrow X) beyond the predetermined position. Since thecushion segment 43a is deformed in the circumferential direction, the driving-side rotator 35 is allowed to rotate beyond the predetermined position in the counter-clockwise direction (the direction of the arrow X), as shown in FIG. 11. - The other side surface (counter-clockwise side surface) 43c of each
cushion segment 43a engages asecond cushion surface 29g, which is formed at a radially inward region of a counter-clockwise side surface of the engagingprojection 29b, when the driving-side rotator 35 is rotated to a predetermined position in the clockwise direction (direction of an arrow Y) relative to the driven-side rotator 29. The other side surface (clockwise side surface) 42c formed at the radially inward region of theprotrusion 42 engages a secondengaging surface 29h, which is formed at a radially outward region of the counter-clockwise side surface of the engagingprojection 29b, when the driving-side rotator 35 is further rotated in the clockwise direction (the direction of the arrow Y) beyond the predetermined position. Since thecushion segment 43a is deformed in the circumferential direction, the driving-side rotator 35 is allowed to rotate beyond the predetermined position in the clockwise direction (the direction of the arrow Y). - With reference to FIG. 11, each
component element 32 is placed at thecenter portion 41a of thecorresponding control surface 41 when the oneside surface 42b of the correspondingprotrusion 42 engages the firstengaging surface 29f of the engagingprojection 29b, and afirst urging surface 42d formed at the radially outward region of the counter-clockwise side surface of theprotrusion 42 engages thecorresponding roller support 33c (FIG. 11). - An
annular sensor magnet 45 is secured around theshaft portion 35a of the driving-side rotator 35. Theannular sensor magnet 45 has a plurality of north poles and a plurality of south poles alternately arranged in a circumferential direction of theannular sensor magnet 45. Amagnetic sensing element 46, such as a Hall element or a magneto-resistive element, is provided in thebrush holder 9 near thesensor magnet 45. Themagnetic sensing element 46 measures a change in magnetic field during rotation of thesensor magnet 45 to measure a rotational speed of therotatable shaft 6, which rotates together with the driving-side rotator 35. - In the
motor 1 of the power window system, when the motor main body 2 is driven to rotate therotatable shaft 6 in the counter clockwise direction (the direction of the arrow X) in FIG. 10, the driving-side rotator 35 (protrusions 42) rotates integrally with therotatable shaft 6 in the same direction (the direction of the arrow X). As shown in FIG. 11, when the oneside surface 42b of the correspondingprotrusion 42 engages the firstengaging surface 29f of the engagingprojection 29b, and thefirst urging surface 42d of theprotrusion 42 engages thecorresponding roller support 33c, the corresponding rollingelement 32 is placed at thecenter portion 41a of the corresponding control surface 41 (this position is hereinafter referred to as a "neutral position"). In this case, the oneside surface 43b of eachcushion segment 43a first engages thefirst cushion surface 29e of the engagingprojection 29b before the oneside surface 42b of theprotrusion 42 engages the firstengaging surface 29f of the engagingprojection 29b, resulting in reduced shocks at the time of engagement. - At this neutral position, each rolling
element 32 is not clamped between thecorresponding control surface 41 of the engagingprojection 29b and the innerperipheral surface 31d of thecollar 31, so that the driven-side rotator 29 is allowed to rotate relative to thecollar 31. Thus, when the driving-side rotator 35 is further rotated in the counter-clockwise direction, the rotational force of the driving-side rotator 35 is transmitted to the driven-side rotator 29 via theprotrusions 42, so that the driven-side rotator 29 is rotated along with the driving-side rotator 35. At this time, the rotational force is applied to eachroller support 33c (support member 33) from thefirst urging surface 42d of the correspondingprotrusion 42 in the same direction (the direction of the arrow X), so that the roller supports 33c (support member 33) are rotated together with the rollingelements 32 in the same direction. - Alternatively, when the
rotatable shaft 6 is rotated in the clockwise direction (the direction of the arrow Y) in FIG. 10, each rollingelement 32 is positioned in the neutral position by the correspondingprotrusion 42. At this neutral position, each rollingelement 32 is not clamped between thecorresponding control surface 41 of the engagingprojection 29b and the innerperipheral surface 31d of thecollar 31, so that the driven-side rotator 29 is allowed to rotate relative to thecollar 31. Thus, the rotational force of the driving-side rotator 35 is transmitted to the driven-side rotator 29 through theprotrusions 42, so that the driven-side rotator 29 is rotated along with the driving-side rotator 35. As a result, theworm shaft 23 is rotated, and theworm wheel 24 and theoutput shaft 25 are rotated synchronously with the rotation of theworm shaft 23. Therefore, the window regulator connected to theoutput shaft 25 is activated to raise or lower the window glass. - When the
motor 1 is not actuated, a load applied to theoutput shaft 25 from the load side (window glass side) causes the driven-side rotator 29 (worm shaft 23) to rotate. Then, when the driven-side rotator 29 is rotated in the clockwise direction (the direction of the arrow Y) in FIG. 10, each rollingelement 32 moves toward thecircumferential end 41b of thecontrol surface 41 of the corresponding engagingprojection 29b. Thereafter, as shown in FIG. 12, when the rollingelement 32 reaches theintermediate portion 41d, the rollingelement 32 is clamed between thecontrol surface 41 and the innerperipheral surface 31d of the collar 31 (locked state). Since theouter ring 31a is secured, the driven-side rotator 29 cannot be rotated further, so that the driving-side rotator 35 cannot be rotated by the driven-side rotator 29. - On the other hand, when the driven-
side rotator 29 is rotated by the above load in the counter-clockwise direction (the direction of the arrow X) in FIG. 10, each rollingelement 32 moves toward thecircumferential end 41c of thecontrol surface 41 of the corresponding engagingprojection 29b. Then, when the rollingelement 32 reaches theintermediate portion 41d, the rollingelement 32 is clamped between thecontrol surface 41 and the innerperipheral surface 31d of thecollar 31a (locked state) . Since theouter ring 31a is secured, the driven-side rotator 29 cannot be rotated further, so that the driving-side rotator 35 cannot be rotated by the driven-side rotator 29. - As described above, even if the relatively large load is applied to the
output shaft 25 from the load side (window glass side), the rotation of the driven-side rotator 29 is prevented. Thus, the window glass, which is connected to theoutput shaft 25, is effectively prevented from moving upward and downward by its own weight or an external force. - At an assembling operation of the
motor 1 of the power window system, when theyoke 4, which has thearmature 7, thebrush holder 9 and the other components installed therein, is connected to thegear housing 21, which has theworm shaft 23 and the other components installed therein, the clutch 20 is assembled. More specifically, with reference to FIG. 9, the driving-side rotator 35 is previously installed to therotatable shaft 6, and the components of the clutch 20 other than the driving-side rotator 35 are previously installed in thegear housing 21. When theyoke 4 and thegear housing 21 are connected together, the driving-side rotator 35 is placed in a predetermined position relative to the driven-side rotator 29, thesupport member 33 and the like, and thus the assembly of the clutch 20 is completed. - Even if the misalignment between the rotational axis of the driving-
side rotator 35 and the rotational axis of the rotatable shaft 6 (e.g., the tilt of the rotational axis of therotatable shaft 6 relative to the rotational axis of the driving-side rotator 35, or the radial displacement of the rotational axis of therotatable shaft 6 relative to the rotational axis of the driving-side rotator 35, which extends parallel to the rotational axis of the rotatable shaft 6) occurs at the time of assembly of the motor, for example, due to the manufacturing error of each corresponding connecting portion, the misalignment is permitted since the sizes of the corresponding components are selected to allow the loose fit of the connectingportion 6a of therotatable shaft 6 within the connectinghole 35e of the driving-side rotator 35. Thus, the application of the relatively large radial loads to the connection between the driving-side rotator 35 and therotatable shaft 6 is restrained. Furthermore, even if theworm shaft 23 is flexed during its rotation to cause the tilt of the driving-side rotator 35, which in turn results in the misalignment between the rotational axis of the driving-side rotator 35 and the rotational axis of therotatable shaft 6, the application of the relatively large radial loads to the connection between the driving-side rotator 35 and therotatable shaft 6 is also effectively restrained. As a result, generation of the relatively large noises and vibrations at the connection between the driving-side rotator 35 and therotatable shaft 6 during the rotation is effectively restrained. - Furthermore, although the connecting
portion 6a of therotatable shaft 6 is loosely fitted within the connectinghole 35e of the driving-side rotator 35, the driving-side rotator 35 is resiliently held around therotatable shaft 6 by the resilient holdingportion 38 provided at the connectinghole 35e to restrain the driving-side rotator 35 from falling off therotatable shaft 6. Thus, in the assembling operation, even when the driving-side rotator 35 is installed around the lower end of therotatable shaft 6, as shown in FIG. 9, or even when centrifugal force is applied to the driving-side rotator 35 in a direction of pulling the driving-side rotator 35 out of therotatable shaft 6, the driving-side rotator 35 is effectively held around therotatable shaft 6 without causing falling off of the driving-side rotator 35 from therotatable shaft 6. Thus, the assembling operation of themotor 1 is accelerated. - The above embodiment provides the following advantages.
- (1) The connecting
portion 6a of therotatable shaft 6 is connected to the connectinghole 35e of the driving-side rotator 35, which includes the two diametrically opposing flat inner wall surfaces, by loosely fitting the connectingportion 6a within the connectinghole 35e in a manner that allows integral rotation of therotatable shaft 6 with the driving-side rotator 35. Thus, the certain amount of misalignment between the rotational axis of therotatable shaft 6 and the rotational axis of the driving-side rotator 35, which is caused, for example, by the manufacturing error of each corresponding connecting portion, is permitted at the time of the assembly. As a result, the application of the relatively large radial loads to the connection between the driving-side rotator 35 and therotatable shaft 6 can be restrained. Furthermore, even when theworm shaft 23 is flexed during its rotation to cause the tilt of the driving-side rotator 35, which in turn results in the misalignment between the rotational axis of the driving-side rotator 35 and the rotational axis of therotatable shaft 6, the application of the relatively large radial loads to the connection between the driving-side rotator 35 and therotatable shaft 6 is effectively restrained. As a result, generation of the relatively large noises and the vibrations from the connection between the driving-side rotator 35 and therotatable shaft 6 during the rotation is effectively restrained. - (2) The driving-
side rotator 35 is produced by the resin molding, and themetal plate 37 having the connectinghole 37c is insert molded within the driving-side rotator 35. The connectinghole 37c of themetal plate 37 is disposed in the connectinghole 35e of the driving-side rotator 35 and has the cross sectional shape substantially coinciding with the cross sectional shape of the connectinghole 35e to directly engage with the connectingportion 6a of therotatable shaft 6 in the rotational direction. Since the connectinghole 37c of themetal plate 37 is constructed to engage with therotatable shaft 6 in the rotational direction, the rigidity of the connection between the driving-side rotator 35 and therotatable shaft 6 is increased in comparison to the driving-side rotator entirely made of the resin material. As a result, the axial size of the connection (connectinghole 35e) of the driving-side rotator 35 can be reduced, allowing a reduction in the axial size of the driving-side rotator 35. Furthermore, the reduction in the axial size of the connection (connectinghole 35e) of the driving-side rotator 35 allows an increase in the allowed tilt angle of therotatable shaft 6 relative to the driving-side rotator 35. Thus, even when the tilt angle of therotatable shaft 6 is relatively large, it is relatively easy to counteract this. Furthermore, since themetal plate 37 is insert molded within the driving-side rotator 35, a separate assembling operation of themetal plate 37 to the driving-side rotator 35 is not required. - (3) The driving-
side rotator 35 has the resilient holdingportion 38, which resiliently holds the driving-side rotator 35 about therotatable shaft 6 to restrain the driving-side rotator 35 from falling off therotatable shaft 6 at the time of assembly. That is, the connectinghole 35e of the driving-side rotator 35 is constructed to loose fit with the rotatable shaft 6 (connectingportion 6a) to permit the certain amount of the misalignment between the rotational axis of therotatable shaft 6 and the rotational axis of the driving-side rotator 35. If the resilient holdingportion 38 is not provided, the driving-side rotator 35 falls off therotatable shaft 6 in the assembling operation, for example, when the connectingportion 6a of therotatable shaft 6 is oriented downwardly, or when the centrifugal force is applied to the driving-side rotator 35 in the direction of pulling the driving-side rotator 35 out of therotatable shaft 6. Thus, the resilient holdingportion 38 restrains the fall of the driving-side rotator 35 from therotatable shaft 6, allowing more freedom in the assembling operation of themotor 1. Since the resilient holdingportion 38 is integrally molded to the driving-side rotator 35, the assembling operation of the resilient holdingportion 38 to the driving-side rotator 35 is not required. Furthermore, generation of relatively large vibrations between therotatable shaft 6 and the driving-side rotator 35 during the rotation of themotor 1 can be restrained by the resilient holding force of the resilient holdingportion 38. - (4) Each of the connecting
portion 6a of therotatable shaft 6 and the connectinghole 35e of the driving-side rotator 35 has the diametrically opposing flat wall surfaces. Thus, the connectingportion 6a and the connectinghole 35e can be relatively easily manufactured. Furthermore, the engagement between the connectingportion 6a of therotatable shaft 6 and the connectinghole 35e of the driving-side rotator 35 can be enhanced in the rotational direction due to the fact that the connectingportion 6a and the connectinghole 35e engage with each other at the two points in the rotational direction. - (5) The connecting
portion 6a of therotatable shaft 6 is formed as the projection. Thus, the connection between therotatable shaft 6 and the driving-side rotator 35 can be easily manufactured. Particularly, since the connectingportion 6a is formed at the end of the axially elongatedrotatable shaft 6, the connectingportion 6a in the form of the projection can be relatively easily formed. - (6) The positioning means in the form of the
positioning holes 9d and thepositioning projections 21n is arranged between thebrush holder 9, which supports therotatable shaft 6, and thegear housing 21, which supports theworm shaft 23. Thebrush holder 9 and thegear housing 21 are directly positioned relative to each other by the positioning means. As a result, accumulation of the errors between therotatable shaft 6 and theworm shaft 23 is reduced, thus effectively restraining the misalignment between the rotational axis of therotatable shaft 6 and the rotational axis of the worm shaft 23 (e.g., tilt of one of the rotational axis of therotatable shaft 6 and the rotational axis of theworm shaft 23 relative to the other, or the radial displacement between the rotational axis of therotatable shaft 6 and the rotational axis of theworm shaft 23, which extend parallel to each other). Therefore, application of relatively large radial loads at the connection between therotatable shaft 6 and the clutch 20 (driving-side rotator 35) can be restrained to restrain generation of the relatively large noises and vibrations at the connection between therotatable shaft 6 and the clutch 20 (driving-side rotator 35). - (7) The positioning means in the form of the
positioning holes 9d and thepositioning projections 21n is arranged radially inward of theclamp portion 9c of thebrush holder 9, which is clamped between theyoke housing 4 and thegear housing 21. Thus, the positioning means is not disposed outside of thesehousings - (8) The relative positioning between the
brush holder 9 and thegear housing 21 is carried out by engaging the positioning holes 9d to thepositioning projections 21n, respectively. Thus, the positioning means can be easily implemented. - (9) The two
positioning projections 21n and the twopositioning holes 9d are arranged. Thus, thebrush holder 9 and thegear housing 21 can be more accurately positioned relative to each other. As a result, the misalignment between the rotational axis of therotatable shaft 6 and the rotational axis of theworm shaft 23 can be minimized. - (10) The two
positioning projections 21n are symmetrically arranged about therotatable shaft 6 at the opposite diagonal corners, and the twopositioning holes 9d are symmetrically arranged about therotatable shaft 6 at the diagonal corners. Thus, thebrush holder 9 and thegear housing 21 can be more accurately positioned relative to each other. As a result, the misalignment between the rotational axis of therotatable shaft 6 and the rotational axis of theworm shaft 23 can be minimized. -
- The above embodiment can be modified as follows.
- In the above embodiment, each of the connecting
portion 6a of therotatable shaft 6 and the connectinghole 35e of the driving-side rotator 35 has the diametrically opposing flat wall surfaces. However, the cross section of each of the connectingportion 6a of therotatable shaft 6 and the connectinghole 35e of the driving-side rotator 35 can have any other shape, such as a polygonal shape (e.g., a quadrangular shape, a hexagonal shape), which allows engagement between the connectingportion 6a of therotatable shaft 6 and the connectinghole 35e of the driving-side rotator 35 in the rotational direction. - Furthermore, as shown in FIGS. 13 and 14, the connecting
portion 6b of therotatable shaft 6 can have a star shaped cross section. That is, the connectingportion 6b has six radially extending projections, and each projection has a trapezoidal cross section. Also, the connecting hole 35g of the driving-side rotator 35 has a corresponding star shaped cross section (the connectinghole 37d of themetal plate 37 also has the corresponding star shaped cross section). Similar to the above embodiment, the connecting hole 35g of the driving-side rotator 35 and the connectingportion 6b of therotatable shaft 6 are sized such that the connecting hole 35g and the connectingportion 6b are loosely fitted together (providing a space S between the connecting hole 35g and the connectingportion 6b). That is, similar to the above embodiment, a certain amount of misalignment between the rotational axis of therotatable shaft 6 and the rotational axis of the driving-side rotator 35 is permitted. Furthermore, the connectingportion 6b having the star shaped cross section achieves the rigidity higher than that of the connectingportion 6b having the diametrically opposing flat wall surfaces. Thus, when the output power of the motor 1 (motor main body 2) is increased, use of the star shaped connectingportion 6b is preferred. - In the example shown in FIGS. 13 and 14, a
cylindrical portion 6c extends continuously from the connectingportion 6b in therotatable shaft 6. Theresilient holding portion 38a of the driving-side rotator 35 is closely engaged with and is resiliently held around thecylindrical portion 6c to restrain falling off of the driving-side rotator 35 from therotatable shaft 6. In this case, the resilient holdingportion 38a is closely engaged with the entire circumference of thecylindrical portion 6c, so that the relatively large resilient holding force can be achieved to restrain the falling off of the driving-side rotator 35 from therotatable shaft 6. - Furthermore, as shown in FIGS. 15A and 15B, a connecting
recess 6d can be formed at the distal end surface of therotatable shaft 6, and a connectingprojection 35h for engaging with the connectingrecess 6d can be formed in the driving-side rotator 35. The connectingrecess 6d and the connectingprojection 35h can have the diametrically opposed flat wall surfaces or can have the polygonal cross section (e.g., the quadrangular shape, the hexagonal shape) or the star shape cross section to engage with each other in the rotational direction in a manner similar to that described above. - Furthermore, like the majority of the rest of the driving-
side rotator 35, a central core portion of the connectingprojection 35h is made of the resin material. Also, ametal plate 39 is secured to an axially middle part of the connectingprojection 35h to directly engage with the connectingrecess 6d of therotatable shaft 6 in the rotational direction. Themetal plate 39 has a cross sectional shape, which corresponds to that of the connectingrecess 6d of therotatable shaft 6. Similar to the above embodiment, themetal plate 39 and the connectingrecess 6d are sized such that themetal plate 39 is loosely fitted within the connectingrecess 6d of therotatable shaft 6, thereby forming a space S therebetween. A resilient holdingportion 40 is integrally formed around the connectingprojection 35h except themetal plate 39. The resilient holdingportion 40 is closely engaged with an inner wall of the connectingrecess 6d of therotatable shaft 6 to resiliently hold the driving-side rotator 35 around therotatable shaft 6 to restrain the driving-side rotator 35 from falling off therotatable shaft 6 at the time of assembly of themotor 1. - In the modification shown in FIG. 15, similar to the above embodiment, when the misalignment between the rotational axis of the
rotatable shaft 6 and the rotational axis of the driving-side rotator 35 occurs at the time of assembly of themotor 1, the misalignment is permitted due to the fact that themetal plate 39 of the connectingprojection 35h is loosely fitted within the connectingrecess 6d of therotatable shaft 6. - The modification of the shape of the
metal plate 37 is not limited to theabove metal plate 39, andmetal plate 37 can be further modified in any appropriate form. Furthermore, in the above embodiment, themetal plate 37 is insert molded within the driving-side rotator 35. However, themetal plate 37 can be separately manufactured from the driving-side rotator 35 and can be assembled to the driving-side rotator 35. Furthermore, if the resin material of the driving-side rotator 35 has an enough rigidity, themetal plate 37 can be eliminated, as shown in FIG. 16. - The shape and the material of the resilient holding
portion 38 of the above embodiment are not limited to ones described above and can be changed to any ones. Furthermore, the resilient holdingportion 38 is integrally molded in the driving-side rotator 35 in the above embodiment. However, the resilient holdingportion 38 can be manufactured separately from the driving-side rotator 35 and can be assembled to the driving-side rotator 35. Furthermore, a resilient holding portion can be provided in therotatable shaft 6. Also, if there is no possibility for the driving-side rotator 35 to fall off therotatable shaft 6 during the assembly (for example, in a case where the connectingportion 6a is upwardly oriented, and the driving-side rotator 35 is installed to the upwardly oriented connectingportion 6a), the resilient holdingportion 38 can be eliminated. - In the above embodiment, the driven-
side rotator 29 is integrally formed with theworm shaft 23. However, the driven-side rotator 29 can be formed separately from theworm shaft 23 and can be assembled to theworm shaft 23. - In the above embodiment, the positioning means for positioning the
brush holder 9 and thegear housing 21 relative to each other includes thepositioning holes 9d and thepositioning projections 21n. The shapes, the positions and the number of thepositioning holes 9d and thepositioning projections 21n can be changed to any appropriate ones. - For example, in the above embodiment, the
positioning holes 9d are provided in thebrush holder 9, and thepositioning projections 21n are provided in thegear housing 21. Alternatively, the positioning projections can be provided in thebrush holder 9, and the positioning holes can be provided in thegear housing 21. - Furthermore, in the above embodiment, the number of the
positioning holes 9d is two, and the number of thepositioning projections 21n is two. Alternatively, only onepositioning hole 9d and the corresponding onepositioning projection 21n can be provided. Also, more than twopositioning holes 9d and the corresponding number of thepositioning projections 21n can be provided. - In the above embodiment, each
positioning hole 9d has the circular cross section, and eachpositioning projection 21n has the cylindrical shape. Alternatively, eachpositioning hole 9d can have a polygonal cross section, and eachpositioning projection 21n can have a polygonal projection. - In the above embodiment, the
positioning projections 21n are symmetrically arranged about therotatable shaft 6 at the diagonal corners, and thepositioning holes 9d are also symmetrically arranged about therotatable shaft 6 in opposed relationship to thecorresponding positioning projections 21n. Alternatively, thepositioning projections 21n can be symmetrically arranged about therotatable shaft 6 at any positions generally along the longitudinal direction of the cross section of the elongated open end of thehousing 21, and thepositioning holes 9d can be also symmetrically arranged about therotatable shaft 6 in opposed relationship to thecorresponding positioning projections 21n. - The structure of the clutch 20 of the above embodiment can be modified in any appropriate manner. For example, in the above embodiment, the clutch 20 is constructed such that each rolling
element 32 is clamped between thecorresponding control surface 41 of the driven-side rotator 29 and the innerperipheral surface 31d of thecollar 31 to lock the driven-side rotator 29, thereby preventing transmission of the rotational force from the load side to the driving-side rotator 35 through the driven-side rotator 29. Alternatively, the clutch can be constructed such that the rotation of the driven-side rotator 29 is allowed while predetermined frictional force is applied to the driven-side rotator 29 from the innerperipheral surface 31d of thecollar 31 and each rollingelement 32, which is clamped between thecorresponding control surface 41 of the driven-side rotator 29 and the innerperipheral surface 31d of thecollar 31. - In the above embodiment, the clutch 20 is used as the coupling means for drivingly coupling the
rotatable shaft 6 to theworm shaft 23. In place of the clutch 20, any other coupling means for drivingly coupling therotatable shaft 6 to theworm shaft 23 can be used. - The structures of the motor main body 2 and the
speed reducing unit 3 of the above embodiment can be modified in any appropriate manner. - In the above embodiment, the
motor 1 is used as the drive source of the power window system. Themotor 1 can be used as a drive source of any other devices and systems. - Additional advantages and modifications will readily occur to those skilled in the art. The invention in its broader terms is therefore, not limited to the specific details, representative apparatus, and illustrative examples shown and described.
Claims (15)
- A motor comprising:a motor main body (2), which includes a rotatable shaft (6) and rotates the rotatable shaft (6);a speed reducing unit (3), which is connected to the motor main body (2) and includes a worm shaft (23), wherein the worm shaft (23) is substantially coaxial with the rotatable shaft (6); anda coupling means (20) for coupling the rotatable shaft (6) with the worm shaft (23), wherein the coupling means (20) includes:a driving-side rotator (35), which is connected with the rotatable shaft (6) to rotate integrally with the rotatable shaft (6); anda driven-side rotator (29), which is connected with the worm shaft (23) to rotate integrally with the worm shaft (23) and is engageable with the driving-side rotator (35) in a rotational direction, wherein:the rotatable shaft (6) includes a connecting portion (6a); andthe driving-side rotator (35) includes a connecting portion (35e), which is loosely fitted with the connecting portion (6a) of the rotatable shaft (6) and is engageable with the connecting portion (6a) of the rotatable shaft (6) in the rotational direction to rotate integrally with the connecting portion (6a) of the rotatable shaft (6).
- A motor according to claim 1, wherein:the driving-side rotator (35) is made by resin molding; andthe driving-side rotator (35) further includes a metal plate (37), which is integrally formed with the connecting portion (35e) of the driving-side rotator (35) and is directly engageable with the connecting portion (6a) of the rotatable shaft (6) in the rotational direction to rotate integrally with the connecting portion (6a) of the rotatable shaft (6).
- A motor according to claim 2, wherein the metal plate (37) is insert molded in the driving-side rotator (35).
- A motor according to claim 2 or 3, wherein:the connecting portion (35e) of the driving-side rotator (35) is a connecting hole (35e), within which the connecting portion (6a) of the rotatable shaft (6) is loosely fitted; andthe metal plate (37) includes an engaging hole (37c), which has a cross sectional shape substantially corresponding to that of the connecting hole (35e) of the driving-side rotator (35) and is disposed in the connecting hole (35e) of the driving-side rotator (35) to directly engage with the connecting portion (6a) of the rotatable shaft (6) in the rotational direction to rotate integrally with the connecting portion (6a) of the rotatable shaft (6).
- A motor according to any one of claims 1 to 4, wherein the driving-side rotator (35) further includes a resilient holding portion (38) for resiliently holding the driving-side rotator (35) around the rotatable shaft (6), so that the driving-side rotator (35) is restrained from falling off the rotatable shaft (6) during assembly of the motor.
- A motor according to claim 5, wherein the resilient holding portion (38) is integrally molded to the driving-side rotator (35).
- A motor according to claim 1, wherein:the coupling means (20) is a clutch (20);the clutch (20) transmits rotational force of the rotatable shaft (6) to the worm shaft (23) through the driving-side rotator (35) and the driven-side rotator (29); andthe clutch (20) prevents transmission of rotational force of the worm shaft (23) from the driven-side rotator (29) to the driving-side rotator (35).
- A motor according to claim 1, wherein:the coupling means (20) is a clutch (20);the clutch (20) transmits rotational force of the rotatable shaft (6) to the worm shaft (23) through the driving-side rotator (35) and the driven-side rotator (29); andthe clutch (20) transmits rotational force of the worm shaft (23) from the driven-side rotator (29) to the driving-side rotator (35) while exerting a predetermined frictional force in the driven-side rotator (29).
- A motor comprising:a motor main body (2), which includes a yoke housing (4), wherein the yoke housing (4) rotatably receives an armature (7), which includes a rotatable shaft (6) and a commutator (8);a brush holder (9), which is placed in an opening of the yoke housing (4), wherein the brush holder (9) holds a plurality of brushes (10) in sliding contact with the commutator (8) and includes a bearing (12), which rotatably supports the rotatable shaft (6);a speed reducing unit (3), which includes a gear housing (21) connected to the yoke housing (4) in such a manner that the brush holder (9) is arranged between an opening of the gear housing (21) and the opening of the yoke housing (4), wherein the gear housing (21) rotatably receives a worm shaft (23), which is substantially coaxial with the rotatable shaft (6);a coupling means (20) for coupling the rotatable shaft (6) with the worm shaft (23); anda positioning means (9d, 21n) for positioning the brush holder (9) and the gear housing (21) relative to each other, wherein the positioning means (9d, 21n) is placed between the brush holder (9) and the gear housing (21).
- A motor according to claim 9, wherein:the brush holder (9) includes a clamp portion (9c), which is clamped between the opening of the gear housing (21) and the opening of the yoke housing (4) along substantially an entire inner perimeter of the opening of the yoke housing (4); andthe positioning means (9a, 21n) is positioned radially inward of the clamp portion (9c).
- A motor according to claim 9 or 10, wherein the positioning means (9a, 21n) includes:at least one positioning projection (21n), which is provided in one of the brush holder (9) and the gear housing (21); andat least one positioning hole (9d), which is provided in the other of the brush holder (9) and the gear housing (21) and is engaged with the at least one positioning projection (21n).
- A motor according to claim 11, wherein:the at least one positioning projection (21n) includes two or more positioning projections (21n); andthe at least one positioning hole (9d) includes two or more positioning holes (9d).
- A motor according to claim 12, wherein:at least two of the two or more positioning projections (21n) are substantially symmetrically arranged about the rotatable shaft (6); andat least two of the two or more positioning holes (9d) are substantially symmetrically arranged about the rotatable shaft (6) in opposed relationship to the at least two, respectively, of the two or more positioning projections (21n).
- A motor according to claim 9, wherein:the coupling means (20) is a clutch (20), which includes a driving-side rotator (35) and a driven-side rotator (29), wherein the driving-side rotator (35) is connected with the rotatable shaft (6) to rotate integrally with the rotatable shaft (6), and the driven-side rotator (29) is connected with the worm shaft (23) to rotate integrally with the worm shaft (23) and is engageable with the driving-side rotator (35) in a rotational direction;the clutch (20) transmits rotational force of the rotatable shaft (6) to the worm shaft (23) through the driving-side rotator (35) and the driven-side rotator (29); andthe clutch (20) prevents transmission of rotational force of the worm shaft (23) from the driven-side rotator (29) to the driving-side rotator (35).
- A motor according to claim 9, wherein:the coupling means (20) is a clutch (20), which includes a driving-side rotator (35) and a driven-side rotator (29), wherein the driving-side rotator (35) is connected with the rotatable shaft (6) to rotate integrally with the rotatable shaft (6), and the driven-side rotator (29) is connected with the worm shaft (23) to rotate integrally with the worm shaft (23) and is engageable with the driving-side rotator (35) in a rotational direction;the clutch (20) transmits rotational force of the rotatable shaft (6) to the worm shaft (23) through the driving-side rotator (35) and the driven-side rotator (29); andthe clutch (20) transmits rotational force of the worm shaft (23) from the driven-side rotator (29) to the driving-side rotator (35) while exerting a predetermined frictional force in the driven-side rotator (29).
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2001127582 | 2001-04-25 | ||
JP2001127582 | 2001-04-25 | ||
JP2001131523 | 2001-04-27 | ||
JP2001131523 | 2001-04-27 |
Publications (3)
Publication Number | Publication Date |
---|---|
EP1253700A2 true EP1253700A2 (en) | 2002-10-30 |
EP1253700A3 EP1253700A3 (en) | 2009-06-03 |
EP1253700B1 EP1253700B1 (en) | 2011-01-19 |
Family
ID=26614181
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP02009157A Expired - Lifetime EP1253700B1 (en) | 2001-04-25 | 2002-04-24 | Motor having rotatable shaft coupled with worm shaft |
Country Status (4)
Country | Link |
---|---|
US (2) | US6727613B2 (en) |
EP (1) | EP1253700B1 (en) |
KR (1) | KR100704753B1 (en) |
DE (1) | DE60238961D1 (en) |
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FR2854505A1 (en) * | 2003-04-29 | 2004-11-05 | Bosch Gmbh Robert | Brush holder for supporting electrical machine brushes, has casing part that receives electric machine rotor, and has four pieces receiving positioning unit, where each piece has two mutually perpendicular inclined surfaces |
CN101114781B (en) * | 2006-07-28 | 2011-08-17 | 株式会社美姿把 | Electric motor with reduction gear mechanism |
US8814710B2 (en) | 2012-03-09 | 2014-08-26 | Johnson Electric S.A. | Torque transmission assembly and coupling |
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CN101114781B (en) * | 2006-07-28 | 2011-08-17 | 株式会社美姿把 | Electric motor with reduction gear mechanism |
US8814710B2 (en) | 2012-03-09 | 2014-08-26 | Johnson Electric S.A. | Torque transmission assembly and coupling |
Also Published As
Publication number | Publication date |
---|---|
US20020158527A1 (en) | 2002-10-31 |
DE60238961D1 (en) | 2011-03-03 |
US6921994B2 (en) | 2005-07-26 |
EP1253700B1 (en) | 2011-01-19 |
US6727613B2 (en) | 2004-04-27 |
EP1253700A3 (en) | 2009-06-03 |
KR100704753B1 (en) | 2007-04-06 |
KR20020082785A (en) | 2002-10-31 |
US20040164629A1 (en) | 2004-08-26 |
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